Method of filling liquid into function liquid droplet ejection head, and ejection apparatus; method of manufacturing LCD device, organic EL device, electron emission device, PDP device, electrophoretic display device, color filter, and organic EL; and method of forming spacer, metallic wiring, lens, resist, and light diffusion member

ABSTRACT

An ejection apparatus has a carriage which moves relative to a workpiece. A function liquid droplet ejection head is held by the carriage and is provided with an ejection nozzle formed in a nozzle forming surface of a head main body. A liquid supply tank is connected to the ejection head. A cap unit is disposed in a position away from the workpiece and is provided, in a position corresponding to the function liquid droplet ejection head, with a cap which is connected to the suction pump and which is brought into intimate contact with the nozzle forming surface of the function liquid droplet ejection head so that the liquid of the liquid supply tank is filled into a flow passage inside the ejection head by a suction force to be operated upon through the cap. A gate valve is interposed in the liquid supply passage between the ejection head and the liquid supply tank. The gate valve is temporarily closed in the course of filling the liquid into the flow passage inside the ejection head, while maintaining suction by the cap.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method of filling a liquid into aflow passage inside a function liquid droplet ejection head, in which aliquid is filled into the flow passage inside the function liquiddroplet ejection head as represented by an ink jet head. It also relatesto an ejection apparatus using a function liquid droplet ejectionapparatus which is capable of being filled with the liquid in theabove-described method; and to a method of manufacturing a liquidcrystal display (LCD) device, a method of manufacturing an organicelectroluminescence (EL) device, a method of manufacturing an electronemission device, a method of manufacturing a plasma display panel (PDP)device, a method of manufacturing an electrophoretic display device, anda method of manufacturing a color filter, a method of manufacturing anorganic EL; as well as to a method of forming a spacer, a method offorming a metallic wiring, a method of forming a lens, a method offorming a resist, and a method of forming a light diffusion body.

[0003] 2. Description of Related Art

[0004] An ink jet head of an ink jet printer (a liquid droplet ejectionhead) is capable of ejecting very minute ink droplets (liquid droplets)in the form of dots at a high accuracy. Therefore, it is expected toapply the liquid droplet ejection head to the field of manufacturingvarious kinds of parts by using, as the liquid to be ejected, functionliquids such as special inks, photosensitive resins, or the like.

[0005] For example, it is considered to carry out the followingoperations. Namely, an ejection apparatus equipped with a main carriagewhich moves relative to the workpiece such as a substrate of a colorfilter, or the like, is used. A head unit having mounted a plurality offunction liquid droplet ejection heads on a subsidiary carriage which isdetachably held by a main carriage of the ejection apparatus, is carriedinto the ejection apparatus. By the movement of the main carriage inthis state, the head unit is relatively moved against the workpiece tothereby eject the liquid droplet from each of the ejection nozzlesformed in a nozzle forming surface of each of the function liquiddroplet ejection heads. The liquid crystal display device, organic ELdisplay device, or the like, is thus manufactured.

[0006] This kind of ejection apparatus has the following arrangement.Namely, a liquid is supplied from a common tank to each of the functionliquid droplet ejection heads by a slight (or small) head pressure sothat the liquid droplet can be ejected at a higher accuracy by theoperation of a pump part which is assembled into the liquid dropletejection head. In a position which is away from the workpiece of theejection apparatus, there is disposed a cap unit on which a plurality ofcaps to be connected to a suction pump are mounted so as to correspondto the plurality of function liquid droplet ejection heads of the headunit. When a new head unit has been carried into the ejection apparatus,each of the caps is brought into intimate contact with the nozzleforming surface of each of the function liquid droplet ejection heads ina state in which the head unit has been moved to a position facing thecap unit. The liquid inside the liquid supply tank is filled into theflow passage inside each of the function liquid droplet ejection headsby means of the suction force to be operated upon through each of thecaps.

[0007] As described above, even if the suction is carried out by thecaps, the flow speed of the liquid inside the flow passage inside thefunction liquid droplet ejection head lowers or drops. As a result, theair bubbles cannot be successfully removed out of the flow passageinside the function liquid droplet ejection head, thereby causing thepoor ejection or failure in ejection of the liquid droplet under theinfluence of the remaining air bubbles. As a consequence, it becomesnecessary to repeat the suction operations several times, resulting inthe amount of liquid to be consumed at the time of filling, therebycausing a higher running cost.

[0008] In view of the above points, this invention provides a method offilling a liquid into a flow passage inside a function liquid dropletejection head, in which air bubbles can be efficiently removed out ofthe flow passage inside the function liquid droplet ejection head. Italso provides an ejection apparatus which is suitable for carrying outthe above-described method, and a method of manufacturing an LCD device,a method of manufacturing an organic EL device, a method ofmanufacturing an electron emission device, a method of manufacturing aPDP device, a method of manufacturing an electrophoretic display device,a method of manufacturing a color filter, a method of manufacturing anorganic EL, as well as a method of forming a spacer, a method of forminga metallic wiring, a method of forming a lens, a method of forming aresist, and a method of forming a light diffusion body.

SUMMARY OF THE INVENTION

[0009] According to one aspect of this invention, there is provided amethod of filling a liquid into a flow passage inside a function liquiddroplet ejection head having an ejection nozzle formed in a nozzleforming surface of a head main body. The method comprises: bringing acap connected to a suction pump into intimate contact with the nozzleforming surface; and filling a liquid of a liquid supply tank connectedto the function liquid ejection head into the flow passage inside thefunction liquid droplet ejection head. A liquid supply passage betweenthe function liquid droplet ejection head and the liquid supply tank istemporarily closed in a course of filling the liquid into the flowpassage inside the function liquid droplet ejection head whilemaintaining suction by the cap.

[0010] According to another aspect of this invention, there is providedan ejection apparatus having: a carriage which moves relative to aworkpiece; a function liquid droplet ejection head which is held by thecarriage and which is provided with an ejection nozzle formed in anozzle forming surface of a head main body, the function liquid dropletejection head ejecting droplets from the ejection nozzle to theworkpiece while carrying out a relative movement between the carriageand the workpiece; a liquid supply tank which is connected to thefunction liquid droplet ejection head; a cap unit which is disposed in aposition away from the workpiece and which is provided, in a positioncorresponding to the function liquid droplet ejection head, with a capwhich is connected to a suction pump and is brought into intimatecontact with the nozzle forming surface of the function liquid dropletejection head, in a state in which the carriage is moved to a positionfacing the cap unit, so that the liquid of the liquid supply tank isfilled into a flow passage inside the function liquid droplet ejectionhead by a suction force to be operated upon through the cap. Theapparatus comprises: a gate valve interposed in the liquid supplypassage between the function liquid droplet ejection head and the liquidsupply tank, and the gate valve is temporarily closed in a course offilling the liquid into the flow passage inside the function liquiddroplet ejection head while maintaining suction by the cap.

[0011] According to the above-described arrangement, at the time ofclosing the liquid supply passage (at the time of closing the gatevalve), the flow passage inside the function droplet ejection head isreduced in pressure. As a result of subsequent opening of the liquidsupply passage (at the time of opening the gate valve), the liquidsuddenly flows and the flow speed of the liquid in the flow passageinside the function liquid droplet ejection head increases in speed,whereby the air bubbles inside the above-described flow passage areefficiently removed or discharged. Therefore, the number of times ofsuction can be kept to a minimum, the amount of consumption of theliquid can be reduced, and the working efficiency can be improved,resulting in the improvement in the workability.

[0012] The higher the ratio of liquid filling into the flow passageinside the function liquid droplet ejection head before closing theliquid supply passage, the higher the efficiency in the reduction ofpressure in the flow passage inside function liquid droplet ejectionhead. Therefore, preferably, the closing of the liquid supply passage iscarried into effect when the liquid inside the liquid supply tank hasbeen sucked at least up to the cap. In this case, preferably, theejection apparatus further comprises a liquid sensor interposed in asuction passage between the cap and the suction pump, and the temporaryclosing of the gate valve is carried out when, after starting the liquidfilling into the flow passage inside the function liquid dropletejection head, the liquid has been detected by the liquid sensor.

[0013] Preferably, the carriage further comprises a head unit which ismade up of a sub-carriage and a plurality of function liquid dropletejection heads mounted on the sub-carriage, and the cap is provided in aplurality of numbers to correspond to the plurality of function liquiddroplet ejection heads. The gate valve is interposed in each of branchpassages of the liquid supply passage, each of the branch passages beingconnected by branching to each of the function liquid droplet ejectionheads. The liquid sensor is provided in each of the branch passages ofthe suction passages, each of the suction passages being connected toeach of the caps. Each of the gate valves is closed when the liquid isdetected by each of the liquid sensors.

[0014] According to this arrangement, even if the ratio of filling theliquid into the function liquid droplet ejection heads varies from headto head, the gate valve can be closed independently at an appropriatetiming for each of the function liquid droplet ejection heads, resultingin a large improvement in the productivity.

[0015] The shorter the length of the flow passage between the gate valveand the function liquid droplet ejection head, the higher the efficiencyof reduction in pressure after the gate valve has been closed and thesmaller the amount of liquid consumption. Therefore, the gate valve ispreferably mounted on a portion which moves integrally with thecarriage. According to this arrangement, there is no need of securing,in a flow passage between the gate valve and the function liquid dropletejection head, a slack (or sag) for the purpose of following themovement of the head unit that is held on the carriage. This arrangementis advantageous in that the length of the flow passage can be shortened.

[0016] According to this invention, there is provided a method ofmanufacturing an LCD device in which a filter element is formed on asubstrate of a color filter by using the above-described ejectionapparatus. The method comprises the steps of: introducing a filtermaterial into the function liquid droplet ejection head; carrying out arelative scanning between the function liquid droplet ejection head andthe substrate; and selectively ejecting the filter material to form thefilter element.

[0017] According to this invention, there is provided a method ofmanufacturing an organic EL device in which an EL light emitting layeris formed on a pixel on a substrate by using the above-describedejection apparatus. The method comprises the steps of: introducing alight emitting material into the function liquid droplet ejection head;carrying out a relative scanning between the function liquid dropletejection head and the substrate; and selectively ejecting the lightemitting material to form the EL light emitting layer.

[0018] According to this invention, there is provided a method ofmanufacturing an electron emission device in which a fluorescent memberis formed on an electrode by using the above-described ejectionapparatus. The method comprises the steps of: introducing a fluorescentmaterial into the function liquid droplet ejection head; carrying out arelative scanning between the function liquid droplet ejection head andthe substrate; and selectively ejecting the fluorescent material to formthe fluorescent member.

[0019] According to this invention, there is provided a method ofmanufacturing a PDP device in which a fluorescent member is formed on arecessed portion on a back substrate by using the above-describedejection apparatus. The method comprises the steps of: introducing afluorescent material into the function liquid droplet ejection head;carrying out a relative scanning between the function liquid dropletejection head and the substrate; and selectively ejecting thefluorescent material to form the fluorescent member.

[0020] According to this invention, there is provided a method ofmanufacturing an electrophoretic display device in which anelectrophoretic member is formed on a recessed portion on an electrodeby using the above-described ejection apparatus. The method comprisesthe steps of: introducing an electrophoretic material into the functionliquid droplet ejection head; carrying out a relative scanning betweenthe function liquid droplet ejection head and the substrate; andselectively ejecting the electrophoretic material to form theelectrophoretic member.

[0021] As described above, by using the above-described ejectionapparatus in the method of manufacturing an LCD device, the method ofmanufacturing an organic EL device, the method of manufacturing anelectron emission device, the method of manufacturing a PDP device, andthe method of manufacturing an electrophoretic display device, the workof initial filling (or charging) of the function liquid into thefunction liquid droplet ejection head to be used in each of theabove-described methods can be carried out appropriately and smoothly.The scanning by the liquid droplet ejection head is generally mainscanning and subsidiary scanning (sub-scanning). In the case of anarrangement in which one line is constituted by a single liquid dropletejection head, there is carried out only the sub-scanning. In addition,the above-described electron emission device is a generic term toinclude the idea of field emission display (FED) device.

[0022] According to this invention, there is provided a method ofmanufacturing a color filter in which a filter element is arrayed on asubstrate by using the above-described ejection apparatus. The methodcomprises the steps of: introducing a filter material into the functionliquid droplet ejection head; carrying out a relative scanning betweenthe function liquid droplet ejection head and the substrate; andselectively ejecting the filter material to form the filter element.

[0023] In this case, preferably, an overcoat layer is coated on thefilter element, and the method further comprises the steps of:introducing a translucent coating material into the function liquiddroplet ejection head after the filter element has been formed; carryingout a relative scanning between the function liquid droplet ejectionhead and the substrate; and selectively ejecting the coating material toform the overcoat layer.

[0024] According to this invention, there is provided a method ofmanufacturing an organic EL in which pixel inclusive of an EL lightemitting layer is arrayed on a substrate by using the above-describedejection apparatus. The method comprises the steps of: introducing thelight emitting material into the function liquid droplet ejection head;carrying out a relative scanning between the function liquid dropletejection head and the substrate; and selectively ejecting the lightemitting material to form the EL organic layer.

[0025] In this case, between the EL light emitting layer and thesubstrate, there is formed a pixel electrode corresponding to the ELlight emitting layer. The method preferably further comprises the stepsof introducing the liquid electrode material into the function liquiddroplet ejection head; carrying out a relative scanning between thefunction liquid droplet ejection head and the substrate; and selectivelyejecting the liquid electrode material to form the pixel electrode.

[0026] In this case, there is formed an opposite electrode so as tocover the EL light emitting layer. The method preferably furthercomprises the steps of: introducing the liquid electrode material intothe function liquid droplet ejection head; carrying out a relativescanning between the function liquid droplet ejection head and thesubstrate; and selectively ejecting the liquid electrode material toform the opposite electrode.

[0027] According to this invention, there is provided a method offorming a spacer in which a particulate spacer is formed between twosubstrates so as to form a cell gap by using the above-describedejection apparatus. The method comprises the steps of: introducing aparticulate material into the function liquid droplet ejection head;carrying out a relative scanning between the function liquid dropletejection head and at least one of the two substrates; and selectivelyejecting the particulate material to form the opposite electrode.

[0028] According to this invention, there is provided a method offorming a metallic wiring in which a metallic wiring is formed on asubstrate by using the above-described ejection apparatus. The methodcomprises the steps of: introducing a metallic wiring material into thefunction liquid droplet ejection head; carrying out a relative scanningbetween the function liquid droplet ejection head and the substrate; andselectively ejecting the metallic wiring material to form the metallicwiring.

[0029] According to this invention, there is provided a method offorming a lens in which a microlens is formed on a substrate by usingthe above-described ejection apparatus. The method comprises the stepsof: introducing a lens material into the function liquid dropletejection head; carrying out a relative scanning between the functionliquid droplet ejection head and the substrate; and selectively ejectingthe lens material to form the microlens.

[0030] According to this invention, there is provided a method offorming a resist in which a resist of an arbitrary shape is formed on asubstrate by using the above-described ejection apparatus. The methodcomprises the steps of: introducing a resist material into the functionliquid droplet ejection head; carrying out a relative scanning betweenthe function liquid droplet ejection head and the substrate; andselectively ejecting the resist material to form the resist.

[0031] According to this invention, there is provided a method offorming a light diffusion member in which a light diffusion member isformed on a substrate by using the above-described ejection apparatus.The method comprises the steps of: introducing a light diffusionmaterial into the function liquid droplet ejection head; carrying out arelative scanning between the function liquid droplet ejection head andthe substrate; and selectively ejecting the light diffusion material toform the light diffusion member.

[0032] As described above, by using the above-described ejectionapparatus in the method of manufacturing a color filter, the method ofmanufacturing an organic EL, the method of manufacturing a metallicwiring, the method of forming a lens, the method of forming a resist,and the method of forming a light diffusion member, the work of initialfilling (or charging) of the function liquid into the function liquiddroplet ejection head to be used in each of the above-described methodscan be carried out appropriately and smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a sectional view showing the step of forming a bankportion (inorganic-matter bank) in manufacturing an organic EL deviceaccording to this invention;

[0034]FIG. 2 is a sectional view showing the step of forming a bankportion (organic-matter bank) in manufacturing the organic EL deviceaccording to this invention;

[0035]FIG. 3 is a sectional view showing the step of plasma processing(water-affinity processing) in manufacturing the organic EL deviceaccording to this invention;

[0036]FIG. 4 is a sectional view showing the step of plasma processing(water-repellency processing) in manufacturing the organic EL deviceaccording to this invention;

[0037]FIG. 5 is a sectional view showing the step of forming a holeinjection layer (liquid droplet ejection) in the method of manufacturingthe organic EL device according to this invention;

[0038]FIG. 6 is a sectional view showing the step of forming the holeinjection layer (drying) in the method of manufacturing the organic ELdevice according to this invention;

[0039]FIG. 7 is a sectional view showing the step of surfacemodification (droplet ejection) in the method of manufacturing theorganic EL device according to this invention;

[0040]FIG. 8 is a sectional view showing the step of surfacemodification (drying) in the method of manufacturing the organic ELdevice according to this invention;

[0041]FIG. 9 is a sectional view showing the step of blue color (B)light emitting layer forming in the method of manufacturing the organicEL device according to this invention;

[0042]FIG. 10 is a sectional view showing the step of blue color (B)light emitting layer forming (drying) in the method of manufacturing theorganic EL device according to this invention;

[0043]FIG. 11 is a sectional view showing the step of red color (R),green color (G), and blue color (B) light emitting layer forming in themethod of manufacturing the organic EL device according to thisinvention;

[0044]FIG. 12 is a sectional view showing the step of forming oppositeelectrodes in the method of manufacturing the organic EL deviceaccording to this invention;

[0045]FIG. 13 is a sectional view showing the step of sealing in themethod of manufacturing the organic EL device according to thisinvention;

[0046]FIG. 14 is a schematic diagram of a hole injection layer formingapparatus according to this invention;

[0047]FIG. 15 is a schematic diagram of a light emitting layer formingapparatus according to this invention;

[0048]FIG. 16 is an outer perspective view of an imaging apparatusaccording to this invention;

[0049]FIG. 17 is a front view showing an outside of the imagingapparatus according to this invention;

[0050]FIG. 18 is a side view showing an outside of the imaging apparatusaccording to this invention;

[0051]FIG. 19 is a plan view showing an outside of the imaging apparatusaccording to this invention;

[0052]FIG. 20 is a schematic diagram showing a liquid droplet ejectionapparatus of the imaging apparatus according to this invention;

[0053]FIG. 21 is a plan view of a head unit according to this invention;

[0054]FIG. 22 is a side view of the head unit according to thisinvention;

[0055]FIG. 23 is a front view of the head unit according to thisinvention;

[0056]FIG. 24A is an outside perspective view of a piping joint and FIG.24B is a sectional view of the piping joint according to this invention;

[0057]FIG. 25A is an outside perspective view of a function liquiddroplet ejection head and FIG. 25B is a sectional view of the functionliquid droplet ejection head according to this invention;

[0058]FIG. 26 is a side view around a stone base of the ejectionapparatus according to this invention;

[0059]FIG. 27 is a plan view around the stone base of the ejectionapparatus according to this invention;

[0060]FIG. 28 is a front view around the stone base of the ejectionapparatus according to this invention;

[0061]FIG. 29 is a schematic view showing the supporting mode of thestone base of the ejection apparatus according to this invention;

[0062]FIG. 30 is a plan view of an X-axis table of the ejectionapparatus according to this invention;

[0063]FIG. 31 is a side view of the X-axis table of the ejectionapparatus according to this invention;

[0064]FIG. 32 is a front view of the X-axis table of the ejectionapparatus according to this invention;

[0065]FIG. 33 is a perspective view around a main substrate recognitioncamera of the ejection apparatus according to this invention;

[0066]FIG. 34 is a plan view of a Y-axis table of the ejection apparatusaccording to this invention;

[0067]FIG. 35 is a side view of the Y-axis table of the ejectionapparatus according to this invention;

[0068]FIG. 36 is a front view of the Y-axis table of the ejectionapparatus according to this invention;

[0069]FIG. 37 is a perspective view of a main carriage of the Y-axistable according to this invention;

[0070]FIG. 38 is a plan view of the main carriage of the Y-axis tableaccording to this invention;

[0071]FIG. 39 is a perspective view of a common machine base of theejection apparatus according to this invention;

[0072]FIG. 40 is a perspective view of the common machine base of theejection apparatus according to this invention in a state in which thecommon base has been removed;

[0073]FIG. 41 is a side view of the common machine base of the ejectionapparatus according to this invention;

[0074]FIG. 42 is a plan view of the common machine base of the ejectionapparatus according to this invention;

[0075]FIG. 43 is a piping diagram of a function liquid supply andrecovery apparatus of the ejection apparatus according to thisinvention;

[0076]FIG. 44 is a perspective view around pumps of the liquid supplyand recovery apparatus according to this invention;

[0077]FIG. 45 is a plan view around the pumps of the liquid supply andrecovery apparatus according to this invention;

[0078]FIG. 46 is a perspective view around a waste liquid pump of theliquid supply and recovery apparatus according to this invention;

[0079]FIG. 47 is a perspective view of a liquid supply tank of theliquid supply and recovery apparatus according to this invention;

[0080]FIG. 48 is a side view of the liquid supply tank of the liquidsupply and recovery apparatus according to this invention;

[0081]FIG. 49 is a front view of the liquid supply tank of the liquidsupply and recovery apparatus according to this invention;

[0082]FIG. 50 is a perspective view of a rolling unit in a wiping unitaccording to this invention;

[0083]FIG. 51 is a plan view of the rolling unit in the wiping unitaccording to this invention;

[0084]FIG. 52 is a front view of the rolling unit in the wiping unitaccording to this invention;

[0085]FIG. 53 is a perspective view of a wipe-out unit in the wipingunit according to this invention;

[0086]FIG. 54 is a plan view of the wipe-out unit in the wiping unitaccording to this invention;

[0087]FIG. 55 is a front view of the wipe-out unit in the wiping unitaccording to this invention;

[0088]FIG. 56 is a schematic diagram showing the operation of the wipingunit according to this invention;

[0089]FIG. 57 is a outside perspective view of a cleaning unit accordingto this invention;

[0090]FIG. 58 is a front view of the cleaning unit according to thisinvention;

[0091]FIG. 59 is a side view of the cleaning unit according to thisinvention;

[0092]FIG. 60 is a plan view of the cleaning unit according to thisinvention;

[0093]FIG. 61 is an enlarged sectional view of a cap of the cleaningunit according to this invention;

[0094]FIG. 62 is a perspective view of a flushing unit according to thisinvention;

[0095]FIG. 63 is a plan view of the flushing unit according to thisinvention;

[0096]FIG. 64 is a perspective view of a portion disposing gate valvesin liquid supply passages according to this invention; and

[0097]FIG. 65 is a side view of the portion disposing the gate valves inliquid supply passages according to this invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0098] With reference to the accompanied drawings, a detaileddescription will now be made about preferred embodiments of thisinvention. An ejection apparatus of this embodiment is to be built intoa manufacturing line for manufacturing an organic EL device which is akind of so-called flat display device. By using a plurality of functionliquid ejection heads, a function liquid such as light emittingmaterial, or the like, is ejected out of the ejection nozzles (ink jetmethod). There are thus formed an EL light emitting layer and holeinjection layer which form the light emitting function of the organic ELdevice

[0099] In this embodiment, a description will be made first about thestructure of the organic EL device as well as about a method (orprocess) of manufacturing the organic EL device. Thereafter, adescription will be made about an apparatus for manufacturing an organicEL device which is made up of an ejection apparatus for scanning afunction droplet ejection head which is mounted thereon, as well asabout a method of manufacturing the organic EL device.

[0100]FIGS. 1 through 13 show the process of manufacturing an organic ELdevice inclusive of an organic EL element, and also show the structureof the organic EL device. This process is made up of the followingsteps: i.e., a step of forming a bank portion (also referred to as abank forming step); a step of plasma processing; a step of forming lightemitting element which in turn is made up of a step of forming a holeinjection/transport layer, and a step of forming a light emitting layer;a step of forming opposed (opposite or counter) electrodes; and a stepof sealing.

[0101] In the step of forming a bank portion, a bank layer 512 a made ofan inorganic matter (hereinafter also called an inorganic-matter banklayer) and a bank layer 512 b made of an organic matter (also called anorganic-matter bank layer) are laminated in a predetermined position ona circuit element portion 502 and an electrode 511 (also called a pixelelectrode) which are formed in advance on a substrate 501. As described,the step of forming a bank portion includes a step of forming theinorganic-matter bank layer 512 a on a part of the electrode 511 as wellas a step of forming the organic-matter bank layer 512 b on theinorganic-matter bank layer 512 a.

[0102] First, in the step of forming the inorganic-matter bank layer 512a, as shown in FIG. 1, a film of an inorganic matter such as SiO₂, TiO₂,or the like, is formed on an interlayer dielectric 544 b of the circuitelement portion 502 and on the pixel electrode 511 of the circuitelement portion 502. This inorganic-matter bank layer 512 a is formedby, e.g., a chemical vapor deposition (CVD) method, a coating method, asputtering method, or the like, on an entire surface of the interlayerdielectric 544 b and on the pixel electrode 511.

[0103] Thereafter, this inorganic-matter film is subjected to patterningby etching, or the like, to thereby form a lower opening portion 512 cwhich corresponds to the position of forming an electrode surface 511 aof the electrode 511. At this time, it is necessary to form theinorganic-matter bank layer 512 a so as to overlap with the peripheralportion of the electrode 511. By thus forming the peripheral portion(only partly) of the electrode 511 in a manner to overlap with theinorganic-matter bank layer 512 a, the light emitting region of thelight emitting layer 510 (see FIGS. 10-13) can be controlled.

[0104] Then, in the step of forming the organic-matter bank layer 512 b,as shown in FIG. 2, an organic-matter bank layer 512 b is formed on theinorganic-matter bank layer 512 a. The organic-matter bank layer 512 bis etched by the art of photolithography, or the like, to thereby forman upper opening portion 512 d of the organic-matter bank layer 512 b.The upper opening portion 512 d is formed in a position whichcorresponds to the electrode surface 511 a and the lower opening portion512 c.

[0105] As shown in FIG. 2, the upper opening portion 512 d shallpreferably be formed larger than the lower opening portion 512 c andsmaller than the electrode surface 511 a. According to this arrangement,the first laminated portion 512 e enclosing or surrounding the loweropening portion 512 c of the inorganic-matter bank layer 512 a isarranged to extend toward the center of the electrode 511 beyond theorganic-matter bank layer 512 b. By thus bringing the upper openingportion 512 d and the lower opening portion 512 c into communicationwith each other, there is formed an opening portion 512 g which passesor penetrates through the inorganic-matter bank layer 512 a and theorganic-matter bank layer 512 b.

[0106] In the subsequent plasma processing step, there are formed aregion showing an affinity with a liquid and a region showing arepellency against the liquid on the surface of the bank portion 512 andon the surface of the pixel electrode 511 a. This plasma processing stepis largely classified into: a preliminary heating step; a step ofcausing to have an affinity with liquid (a liquid-affinity step) inwhich an upper surface 512 f of the bank portion 512, a wall surface ofthe opening portion 512 g, and an electrode surface 511 a of the pixelelectrode 511 are made to have liquid-affinity (property to show anaffinity with the liquid); a step of causing to have a repellencyagainst liquid (a liquid-repellency step) in which an upper surface 512f of the organic-matter bank layer 512 b and a wall surface of the upperopening portion 512 d are made to have liquid repellency (property toshow a repellency against the liquid); and a cooling step.

[0107] First, in the preliminary heating step, the substrate 501inclusive of the bank portion 512 is heated to a predeterminedtemperature. In heating the substrate 501, a heater is attached to astage on which the substrate 501 is mounted and the substrate 501 isheated by this heater together with the stage. In concrete, it ispreferable to make the preliminary heating temperature to the range of,e.g., 70-80° C.

[0108] Then, in the liquid-affinity step, plasma processing (O₂ plasmaprocessing) is carried out in open air (outside air) with oxygen as aprocessing gas. As a result of this O₂ plasma processing,liquid-affinity processing is carried out, as shown in FIG. 3, on theelectrode surface 511 a of the pixel electrode 511, on the wall surfacesof the first laminated portion 512 e of the inorganic-matter bank layer512 a and of the upper opening portion 512 d of the organic-matter banklayer 512 b, and on the upper surface 512 f. As a result of thisliquid-affinity processing, hydroxyl group is introduced into each ofthese surfaces to thereby give them liquid-affinity properties. Thoseportions which are subjected to the liquid-affinity processing are shownby a chain line.

[0109] In the subsequent liquid-repellency processing step, plasmaprocessing is carried out in the atmosphere of open air with methanetetrafluoride (CF₄) as the processing gas (CF₄ plasma processing). As aresult of CF₄ plasma processing, as shown in FIG. 4, the wall surface ofthe upper opening portion 512 d and the upper surface 512 f of theorganic-matter bank layer are subjected to liquid-repellency processing.As a result of this liquid-repellency processing, fluorine group isintroduced into each of the surfaces to thereby give themliquid-repellency properties. In FIG. 4, the regions showing theliquid-repellency properties are shown by a chain double-dashed line.

[0110] In the subsequent cooling step, the substrate 501 heated by theplasma processing is cooled down to room temperature or to the controltemperature for the liquid droplet ejecting step. By thus cooling theplasma-processed substrate 501 down to the room temperature or to thepredetermined temperature (e.g., to the control temperature at which theliquid droplet ejection step is carried out), the subsequent holeinjection/transport layer forming step can be carried out at a giventemperature.

[0111] Then, in the light emitting element forming step, the holeinjection/transport layer and a light emitting layer are formed on thepixel electrode 511, thereby forming a light emitting element. The lightemitting element forming step is made up of the following four steps:i.e., a first liquid droplet ejection step in which a first compositionof matter for forming the hole injection/transport layer is ejected ontoeach of the pixel electrodes; a hole injection/transport layer formingstep in which the ejected first composition of matter is dried tothereby form the hole injection/transport layer on the pixel electrodes;a second liquid droplet ejection step in which a second composition ofmatter for forming the light emitting layer is ejected onto the holeinjection/transport layer; and a light emitting layer forming step inwhich the ejected second composition of matter is dried to thereby forma light emitting layer on the hole injection/transport layer.

[0112] First, in the first liquid droplet ejection step, the firstcomposition of matter inclusive of the material for forming the holeinjection/transport layer is ejected onto the electrode surface 511 a byink jet method (liquid droplet ejection method). This first liquiddroplet ejection step and the subsequent steps shall preferably becarried out in an atmosphere of an inert gas such as argon gas, or thelike, free from water and oxygen. In case the hole injection/transportlayer is formed only on the pixel electrodes, the holeinjection/transport layer to be formed adjacent to the organic-matterbank layer is not formed.

[0113] As shown in FIG. 5, the first composition of matter inclusive ofthe material for the hole injection/transport layer is filled into afunction liquid droplet ejection head H. An ejection nozzle of thefunction liquid droplet ejection head H is caused to face the pixelelectrode surface 511 a which is positioned inside the lower openingportion 512 c. While moving the function liquid droplet ejection head Hand the substrate 501 relative to each other, the first composition ofmatter 510 c whose amount of liquid per a droplet is kept under controlis ejected from the ejection nozzle toward the electrode surface 511 a.

[0114] As the first composition of matter to be used here, there may beemployed a composition formed by dissolving a mixture of a polythiophenederivative, such as poly(ethylenedioxy)tiophene (PEDOT), and poly(tyrenesulphonicacid) (PSS), or the like, in a polar solvent. As the polarsolvent, there may be mentioned glycol ethers, such as isopropyl alcohol(IPA), normal butanol, γ-utyrolactone, N-methylpyrrolidone (NMP), 1,3dimethyl-2-imidazolidinone (DMI) and derivatives thereof, carbitolacetate, and butylcarbitol acetate. It should be noted that as the holeinjection/transport layer-forming material, there may be used the samematerial for each of the light emitting layers 510 b of red color (R),green color (G), and blue color (B), and also there may be useddifferent materials for the respective light emitting layers.

[0115] As shown in FIG. 5, the ejected first composition of matter 510spreads or extends over the liquid-affinity processed electrode surface511 a and over the first laminated portion 512 e and is filled into thelower and upper opening portions 512 c, 512 d. The amount of the firstcomposition of matter to be ejected onto the electrode surface 511 a isdetermined by the size of the lower and upper opening portions 512 c,512 d, the thickness of the hole injection/transport layer, theconcentration of the material for forming the hole injection/transportlayer in the first composition of matter, or the like. The firstcomposition of matter 510 c may be ejected toward the same electrodesurface 511 a not only in one time but also in several times.

[0116] As shown in FIG. 6, in the hole injection/transport layer formingstep, the ejected first composition of matter is subjected to theprocessing of drying and heat treatment. The polar solvent contained inthe first composition of matter is thus evaporated, and the holeinjection/transport layer 510 a is formed on the electrode surface 511a. By carrying out the drying processing, the evaporation of the polarsolvent contained in the first composition of matter 510 c occurs inportions which are close to the inorganic-matter bank layer 512 a andthe organic-matter bank layer 512 b and, consequently, not only is thepolar solvent evaporated but also is the hole injection/transport layerforming material condensed and deposited. As a result, the evaporationof the polar solvent occurs also on the electrode surface 511 a by thedrying processing. A flat portion 510 a which is made up of the holeinjection/transport layer forming material is thus formed on theelectrode surface 511 a. Since the speed of evaporation of the polarsolvent on the electrode surface 511 a is substantially uniform, thematerial to form the hole injection/transport layer 511 a is uniformlycondensed on the electrode surface 511 a, whereby the flat portion 510 aof a uniform thickness is formed.

[0117] In the subsequent second liquid droplet ejection step, the secondcomposition of matter containing the light emitting layer formingmaterial is ejected by the liquid droplet ejection method. In thissecond liquid droplet ejection step, non-polar solvent which isinsoluble to the hole injection/transport layer 510 a is used as asolvent for the second composition of matter which is used in formingthe light emitting layer, in order to prevent the holeinjection/transport layer 510 a from getting dissolved again.

[0118] On the other hand, since the hole injection/transport layer 510 ais low in affinity to the non-polar solvent, the holeinjection/transport layer 510 a and the light emitting layer 510 bcannot be adhered to each other or the light emitting layer 510 b cannotbe uniformly coated even if the second composition of matter containingthe non-polar solvent is ejected onto the hole injection/transport layer510 a. As a solution, in order to enhance the surface affinity of thehole injection/transport layer 510 a to the nonpolar solvent and thelight emitting layer forming material, it is preferable to carry out thesurface modification step before forming the light emitting layer.

[0119] Therefore, a description will first be made about the surfacemodification step. The surface modification step is carried out bycoating the hole injection/transport layer 510 a with a solvent that isthe same as the non-polar solvent in the first composition of matter orwith a solvent which is similar thereto, by liquid droplet ejectionmethod, spin coating method, or dip coating method and, thereafter,drying it.

[0120] For example, the coating by the liquid droplet ejection method iscarried out in the following manner as shown in FIG. 7. Namely, thefunction liquid droplet ejection head H is filled with a surfacemodification solvent. The ejection nozzle of the function liquid dropletejection head H is caused to face the substrate (i.e., the substrate onwhich the hole injection/transport layer 510 a has been formed). Whilemoving the function liquid droplet ejection head H and the substrate 501relative to each other, the surface modification solvent 510 d isejected from the ejection nozzle H. Then, as shown in FIG. 8, thesurface modification solvent 510 d is dried.

[0121] Then, in the second liquid droplet ejection step, the secondcomposition of matter inclusive of the light emitting layer formingmaterial is ejected by the liquid droplet ejection method onto the holeinjection/transport layer 510 a. As shown in FIG. 9, the function liquiddroplet ejection head H is filled with the second composition of mattercontaining the blue color (B) light emitting layer forming material. Theejection nozzle of the function liquid droplet ejection head H is causedto face the hole injection/transport layer 510 a which is positionedinside the lower and upper opening portions 512 c, 512 d. While movingthe ink jet head H and the substrate 501 relative to each other, thesecond composition of matter 510 e whose amount of flow per each dropletis controlled is ejected from the ejection nozzle onto the holeinjection/transport layer 510 a As the light emitting layer formingmaterial, there may be used polyfluorene-based high polymer derivatives,(poly)paraphenylene vinylene derivatives, polyphenylene derivatives,polyvinylcarbazole, polythiophene derivatives, perylene-based dyes,coumarin-based dyes, and rhodamine-based dyes. Alternatively, it ispossible to use one formed by doping any of the above-described highpolymers with an organic EL element. For example, it is possible to useone doped with rubrene, peryene, 9,10-diophenylanthracene,tetraphenylbutadiene, Nile red, Coumarin-6, quinacridon, or the like.

[0122] As the non-polar solvent, solvents insoluble to the holeinjection/transport layer 510 a are preferable, and there may be used,e.g., cyclohexyl benzen, dihydrobenzofuran, trimethylbenzene,tetramethlbenzened, etc. By using such a non-polar solvent for thesecond composition of the light emitting layer 510 b, it is possible toapply the second composition without causing the holeinjection/transport layer 510 a to be dissolved again.

[0123] As shown in FIG. 9, the ejected second composition of matter 510e is spread or extended over the hole injection/transport layer 510 aand is filled into the lower and upper opening portions 512 c, 512 d.The second composition of matter 510 e may be ejected onto the holeinjection/transport layer 510 a not only in one time but also in severaltimes. In this case, the quantity of the second composition of matter ineach time of ejection may be the same or may be changed from time totime.

[0124] Then, in the light emitting layer forming step, drying processingand heat treating processing are carried out after the secondcomposition of matter has been ejected, whereby a light emitting layer510 b is formed on the hole injection/transport layer 510 a. In thedrying processing, the ejected second composition of matter is subjectedto drying processing to thereby evaporate the non-polar solventcontained in the second composition of matter. A blue color (B) lightemitting layer 510 b is thus formed as shown in FIG. 10.

[0125] Subsequently, as shown in FIG. 11, a red color (R) light emittinglayer 510 b is formed in the same way as in the case of the blue color(B) light emitting layer 510 b. Finally, a green color (G) lightemitting layer 510 b is formed. It is to be noted that the order offorming the light emitting layers 510 b is not limited to theabove-described order, but may be arbitrarily determined. For example,it is possible to determine the order of forming the light emittinglayers depending on the light emitting layer forming materials.

[0126] Thereafter, in the opposed or opposite electrode forming step, acathode 503 (an opposed electrode) is formed on the entire surface ofthe light emitting layer 510 b and the organic-matter bank layer 512 bas shown in FIG. 12. This cathode 503 may be formed by laminating aplurality of materials. For example, on the side close to the lightemitting layer, it is preferable to form a material with a small workfunction. For example, it is possible to use Ca, Ba, or the like.Depending on the material, on some cases, it is better to thinly formLiF, or the like, on a lower layer. It is further preferable to use onthe upper side (sealing side) a material with a higher work functionthan that on the lower layer. These cathodes (cathode layers) 503 arepreferably formed by vapor deposition method, sputtering method,chemical vapor deposition (CVD) method, or the like. Particularly, it ispreferable to resort to the vapor deposition method in order to preventthe light emitting layer 510 b from being damaged by the heat.

[0127] Lithium fluoride may be formed only on the light emitting layers510 b, and only on the blue color (B) light emitting layer 510 b. Inthis case, the other red color (R) light emitting layer and green color(G) light emitting layer 510 b, 510 b will contact the upper cathodelayer 503 b made from LiF. In addition, on an upper portion of thecathode layer 12, it is preferable to use Al film, Ag film, or the like,which is formed by vapor deposition method, sputtering method, CVDmethod, or the like. Further, on top of the cathode 503, a protectionlayer such as of SiO₂, SiN, or the like, may be provided for the purposeof prevention of oxidation.

[0128] In the sealing step as shown in FIG. 13, a sealing substrate 505is laminated on top of the organic EL element 504 in the atmosphere ofan inert gas such as of nitrogen, argon, helium, or the like. Thesealing step is preferably carried out in the atmosphere of the inertgas of nitrogen, argon, helium, or the like. If the sealing step iscarried out in the atmosphere of open air, there is a possibility ofpenetration of water, oxygen, or the like, into the defect portions ifdefects such as a pin hole, or the like, are present in the cathode 503.The cathode 503 is thus oxidized, which is not preferable. Finally, thecathode 503 is connected to the wiring of the flexible substrate and thewiring of the driving IC circuit element portion 502 is connected,whereby the organic EL device 500 according to this embodiment isobtained.

[0129] A liquid material may be used also in the liquid-repellency film,the cathode 503, the pixel electrode 511, or the like, so that they canbe formed by the liquid droplet ejection method.

[0130] Description will now be made about the apparatus formanufacturing an organic EL device. As described hereinabove, in theprocess for manufacturing the organic EL device, the following steps arecarried out by liquid droplet ejection method. Those steps in questionare: the hole injection/transport layer forming step (first liquiddroplet ejection step+drying step) for forming the holeinjection/transport layer (hole injection layer); the surfacemodification step; and the light emitting layer forming step (secondliquid droplet ejection step+drying step) for forming the light emittinglayer. Corresponding to the above steps, the apparatus for manufacturingthe organic EL device according to this embodiment employs an imagingapparatus (apparatus for making or plotting images or pictures) whichcarries out or performs scanning while ejecting light emitting functionmaterials.

[0131] In concrete, as shown in FIG. 14, a hole injection layer formingapparatus A which carries out the hole injection/transport layer formingstep (inclusive of the surface modification step, if necessary) is madeup of: the above-described ejection apparatus 1 a which has mountedthereon function liquid ejection heads for introducing the first liquiddroplet (light emitting function material: hole injection layermaterial); a drying apparatus 2 a; a substrate transportation apparatus3 a; as well as a chamber apparatus 4 a which contains or houses thereinthe above apparatuses. As described above, it is preferable to carry outthe hole injection/transport layer forming step in the atmosphere of aninert gas. This chamber apparatus 4 a is used as a means for carryingout the step therein.

[0132] The chamber apparatus 4 a is made up of: a main chamber 4 aawhich contains or houses therein the ejection apparatus 1 a; and asubsidiary chamber (subchamber) 4 ab which contains therein the dryingapparatus 2 a and the substrate transportation apparatus 3 a and whichalso contains therein in a tunnel shape the connecting portions(transportation paths) for connecting together the above-describedchambers/apparatuses. The main chamber 4 aa employs a system in which anappropriate or favorable atmosphere is generated therein by causing aninert gas to flow therethrough continuously (details to be describedhereinafter). The sub-chamber 4 ab employs a system in which anappropriate or favorable atmosphere is generated therein by circulatingan inert gas therethrough. In the figure, reference numeral 5 denotes asubstrate transfer apparatus.

[0133] Similarly, as shown in FIG. 15, the light emitting layer formingapparatus B which carries out the light emitting layer forming step ismade up of: the above-described ejection apparatus 1 b having mountedthereon a function liquid droplet ejection head for introducing a secondliquid droplet (light emitting function materials: red (R) green (G)blue (B) light emitting layer materials); a drying apparatus 2 b; asubstrate transportation apparatus 3 b, the above-described apparatusesbeing provided in three sets, one for each of the above-describedcolors; as well as three sets of chamber apparatuses 4 b forrespectively containing therein the above-described apparatuses. In thesame manner as above, it is preferable to carry out the light emittinglayer forming step in the atmosphere of an inert gas. As a means forcarrying it out, there is provided the chamber apparatuses 4 b. Thesechamber apparatuses 4 b are also made up of: three main chambers 4 bafor containing therein respective ejection apparatuses 1 b, and threesub-chambers 4 bb for containing therein respective drying apparatuses 2b and respective substrate transportation apparatuses 3 b and forcontaining therein the respective connecting portions (transportationpaths) for connecting the above chambers/apparatuses.

[0134] It is to be noted that some parts or elements in the followingembodiments are provided in plural numbers instead of only one. In thefollowing detailed descriptions, they will sometimes be referred to in asingular form instead of in a plural form. It is partly for the sake ofsimplicity, or the like, and shall therefore be understood to includeplural form, too, where applicable and appropriate.

[0135] The ejection apparatus 1 a of the hole injection layer formingapparatus A and the ejection apparatus 1 b of the light emitting layerforming apparatus B are different from each other in the liquid materialto be introduced into the respective function liquid droplet ejectionheads and have otherwise the same construction. In addition, the dryingapparatuses 2 a, 2 b, the substrate transportation apparatuses 3 a, 3 b,and the chamber apparatuses 4 a, 4 b have respectively the constructionthat is the same as, or similar to, each other. If the time required forthe exchanging of the function liquid ejection heads or the exchangingof the supply systems for the light emitting function materials is leftout of consideration, it is thus possible to manufacture an organic ELdevice in an arbitrary set of apparatuses (ejection apparatus 1, dryingapparatus 2, substrate transportation apparatus 3, and chamber apparatus4).

[0136] Therefore, in this embodiment, description is made hereinbelowabout the construction of one set of apparatuses on the left end in FIG.15, i.e., the ejection apparatus 1 b for forming a light emitting layerof blue color (B), the drying apparatus 2 b, the substratetransportation apparatus 3 b, and the chamber apparatus 4 b, and thedescription about the other apparatuses is omitted.

[0137] A substrate that has been processed in the above-described bankforming step and the plasma processing step is transported from thesubstrate transfer apparatus 5 which is located at the left end in FIG.15 to the substrate transportation apparatus 3 (3 b) by means of anapparatus (not illustrated), and is changed therein in its direction andposture for being further transported to the ejection apparatus 1 (1 b).The substrate that has been handed over from the substratetransportation apparatus 3 (3 b) to the ejection apparatus 1 (1 b) isset in position on the ejection apparatus 1 (1 b). In the ejectionapparatus 1 (1 b) a light emitting material (liquid droplet) of bluecolor (B) is ejected by the function liquid droplet ejection head to amultiplicity of pixel regions (opening portions 512 g) in the substrate(second liquid droplet ejection step).

[0138] Then, the substrate to which the light emitting material has beencoated or adhered is handed over from the ejection apparatus 1 (1 b) tothe substrate transportation apparatus 3 (3 b), and is introduced by thesubstrate transportation apparatus 3 (3 b) into the drying apparatus 2(2 b). In the drying apparatus 2 (2 b), the substrate is exposed to ahigh-temperature atmosphere of an inert gas for a predetermined periodof time to thereby evaporate the solvent in the light emitting material(drying step). Here, the substrate is again introduced into the ejectionapparatus 1 (1 b) to carry out the second liquid droplet ejection step.In other words, the second liquid droplet ejection step and the dryingstep are repeated for a plurality of times. Once the light emittinglayer has attained a desired thickness, the substrate is transportedthrough the substrate transportation apparatus 3 (3 b) to the centralejection apparatus 1 (1 b) so as to form a light emitting layer of redcolor (R), and is finally transported to the right end ejectionapparatus 1 (1 b) to form therein a light emitting layer of green color(G). These steps are carried out in the atmosphere of an inert gasinside the above-described chamber apparatus 4 (4 b). It is to be notedhere that the order of forming each of the blue, red and green colorlight emitting layers may be arbitrarily selected.

[0139] Detailed descriptions about the drying apparatus 2 and thesubstrate transportation apparatus 3 are omitted. It is, however, to benoted that the drying apparatus 2, for example, shall preferably employa system of using a hot plate or a lamp (infrared lamp), aside from ablow drying system in which an inert gas is blown, a vacuum dryingsystem, or the like. The drying temperature shall preferably be set to40° C. through 200° C.±2° C.

[0140] Detailed description will now be made about the ejectionapparatus 1. The ejection apparatus 1 is made up, as shown in FIGS. 16through 19, of a liquid droplet ejection apparatus (liquid dropletejection means) 10 and an auxiliary apparatus 11. The auxiliaryapparatus 11 is made up of: a liquid supply and recovery apparatus 13which supplies the liquid droplet ejection apparatus 10 with a liquidmaterial and which also recovers the liquid that has become useless(that has been put out of service); an air supply apparatus 14 whichsupplies each of the constituting parts with compressed air for use indriving/controlling, or the like; a vacuum suction apparatus 15 whichsucks air; and a maintenance apparatus 16 which is used for maintenanceof the function liquid droplet ejection head 7; or the like.

[0141] The liquid droplet ejection apparatus 10 is made up of: asupporting rack 21 disposed on a floor; a stone base 22 disposed on thesupporting rack 21; an X-axis table 23 disposed on the stone base 22 anda Y-axis table 24 which crosses the X-axis table 23 at a right angle; amain carriage 25 disposed in a manner to be suspended from the Y-axistable 24; and a head unit 26 mounted on the main carriage 25. The headunit 26 has mounted thereon a plurality of function liquid dropletejection heads 7 (details are given hereinafter). To correspond to theseplurality of function liquid droplet ejection heads 7, a substrate(workpiece) W is set in position on a suction table 81 of the X-axistable 23.

[0142] The liquid droplet ejection apparatus 10 of this embodiment has aconstruction in which the substrate W is moved in a manner synchronizedwith the driving of the function liquid droplet ejection heads 7(selective ejection of the function liquid droplet). The so-called mainscanning of the function liquid droplet ejection heads 7 is carried outby the reciprocating (back and forth) movements of the X-axis table 23in the X-axis direction. The so-called subsidiary scanning(sub-scanning) in correspondence to the main scanning is carried out bythe reciprocating (back and forth) movements of the function liquiddroplet ejection heads 7 in the Y-axis direction by the Y-axis table 24.It is of course possible to carry out the main scanning only by theforward movement (or by the backward movement) in the X-axis direction.

[0143] On the other hand, the home position of the head unit 26 isdefined to be in the left end position as seen in FIGS. 17 and 19. Fromthe left side of this liquid droplet ejection head 10, the head unit 26is brought into or replaced (details will be given hereinafter). To thisside (i.e., to the side of the viewer) of the figure, theabove-described substrate transportation apparatus 3 faces, and thesubstrate W is carried into, or brought out from, this side of thefigure. To the right side, as seen in the figure, of the liquid dropletejection apparatus 10, there are integrally disposed main constitutingapparatuses of the above-described auxiliary apparatus 11.

[0144] The auxiliary apparatus 11 is made up of: a common machine base31 of a cabinet style; the air supply apparatus 14 and the vacuumsuction apparatus 15 which are contained or housed inside one half ofthe common machine base 31; the above-described function liquid supplyand recovery apparatus 13 which is contained in the other one half ofthe common machine base 31; and the above-described maintenanceapparatus 16 which contains the main constituting apparatuses on thecommon machine base 31.

[0145] The maintenance apparatus 16 is made up of: a flushing unit 33 inwhich the function liquid droplet ejection heads 7 are subjected toregular flushing operation (ejection work to discard the function liquidfrom all of the ejection nozzles); a cleaning unit 34 which carries outthe suction and keeping of the function liquid from the function liquiddroplet ejection heads 7; and a wiping unit 35 which wipes out thenozzle forming surfaces of the function liquid droplet ejection heads 7.The cleaning unit 34 and the wiping unit 35 are disposed on the commonmachine base 31.

[0146] The main chamber 4 is made in the form of a so-called clean room,as shown in FIGS. 14 and 15, which has disposed in a chamber room 37 anelectrical room 38 and a mechanical room (or machine room) 39 in a sideby side relationship. The chamber room 37 is filled with nitrogen gaswhich is an inert gas. The above-described liquid droplet ejectionapparatus 10 and the auxiliary apparatus 11 are exposed to theatmosphere of nitrogen gas as a whole and are operated in the atmosphereof nitrogen gas.

[0147] Here, with reference to a schematic diagram in FIG. 20, a briefdescription will be made about the series of operations of the ejectionapparatus 1 which operates in the atmosphere of nitrogen gas. First, asa preparatory step, the head unit 26 is brought into the liquid dropletejection apparatus 10 and is set in position on the main carriage 25.Once the head unit 26 has been set in position on the main carriage 25,the Y-axis table 24 moves the head unit 26 to a position of a headrecognition camera (not illustrated) to thereby recognize the positionof the head unit 26 by means of a head recognition camera. Based on theresult of this recognition, the head unit 26 is corrected in respect ofa Θ axis, and the head unit 26 is subjected to a positional correctionin respect of the X-axis direction and the Y-axis direction in terms ofdata. After the positional correction, the head unit 26 (main carriage25) returns to the home position.

[0148] On the other hand, once the substrate W (in this case, each ofthe substrates to be introduced) is introduced into the suction table 81of the X-axis table 23, a main substrate recognition camera 90 (to bedescribed in detail hereinafter) recognizes the position of thesubstrate at that position (the position of handing over and receiving).Based on the result of this recognition, the substrate W is corrected inrespect of the Θ axis, and a positional correction of the substrate W inrespect of the X-axis direction and the Y-axis direction is carried outin terms of the data. After the positional correction, the substrate W(suction table 81) returns to the home position. At the time of aninitial adjustment of the X-axis table 23 and the Y-axis table 24(so-called center alignment), an alignment mask is introduced onto thesuction table 81 to thereby carry out the initial adjustment by means ofa subsidiary substrate recognition camera 108 which is described indetail hereinafter.

[0149] Once the preparations have been finished as described above, inthe actual liquid droplet ejection operation, the X-axis table 23 isfirst driven to thereby move the substrate W back and forth in the mainscanning direction. The plurality of function liquid droplet ejectionheads 7 are also driven to thereby carry out the selective ejectionoperation of the function liquid droplets toward the substrate W. Afterthe substrate W has returned, the Y-axis table 24 is then driven tothereby move the head unit 26 by one pitch in the subsidiary scanningdirection. The back and forth movements of the substrate W and thedriving of the function liquid droplet ejection heads are carried outagain. By repeating these operations several times, the liquid dropletscan be ejected from end to end over the entire region of the substrateW.

[0150] In this embodiment, the substrate W which is the object to whichthe function liquid droplet ejection is made is moved in the mainscanning direction (X-axis direction) relative to the head unit 26. Itmay also be arranged that the head unit 26 is moved in the main scanningdirection. Or else, there may be employed an arrangement in which thehead unit 26 is fixed or stationary and in which the substrate W ismoved in the main scanning direction and in the sub-scanning direction.

[0151] Then, a description will now be made about the arrangement of theliquid droplet ejection apparatus 10 and the auxiliary apparatus 11.Before proceeding further, in order to facilitate the understanding, adetailed description will be made about the head unit 26 whichconstitutes the main portion of the liquid droplet ejection apparatus10.

[0152]FIGS. 21 through 24 are arrangement drawings of the head unit. Asshown therein, the head unit 26 is made up of: a subsidiary carriage(sub-carriage) 41; a plurality of (twelve) function liquid dropletejection heads 7 which are mounted on the sub-carriage 41; and aplurality of (twelve) head holding members 42 for mounting each of thefunction liquid droplet ejection heads 7 on the sub-carriage 41. Twelvefunction liquid droplet ejection heads 7 are divided into right and leftgroups of six each and are disposed at a predetermined angle to the mainscanning direction.

[0153] The six function liquid droplet ejection heads 7 of one group aredisposed at a positional deviation, in the sub-scanning direction,relative to the six function liquid droplet ejection heads 7 of theother group. In this manner, all of the ejection nozzles 68 (to bedescribed in detail hereinafter) of the twelve function liquid dropletejection heads 7 are continuous (partly overlapped) in the sub-scanningdirection. In other words, the head arrangement in this embodiment issuch that, on the sub-carriage 41, six function liquid droplet ejectionheads 7 disposed at an angle in the same direction are provided in tworows and that the function liquid droplet ejection heads 7 in one of thehead rows are disposed at 180° rotation relative to the other of thehead rows of the function liquid droplet ejection heads 7.

[0154] The above-described arrangement pattern is only one example. Theadjoining function liquid droplet ejection heads 7 within one head rowmay be disposed at an angle of 90° relative to each other, or else thefunction liquid droplet ejection heads 7 of one head row may be disposedat an angle of 90° relative to the function liquid droplet ejectionheads of the other head row. Anyway, as long as the dots by all of theejection heads 68 of the twelve function liquid droplet ejection heads 7are continuous in the sub-scanning direction, they serve the purpose.

[0155] In addition, if the function liquid droplet ejection heads 7 aremade to be parts for exclusive use by each kind of substrate W, it isnot necessary to take the trouble of setting the function liquid dropletejection heads 7 at an inclination. Instead, it is sufficient to arrangethem in a staggered or stepped manner. In more detail, as long as anozzle array (dot array) of a predetermined length can be constituted,they may be constituted by a single function liquid droplet ejectionhead 7 or by a plurality of function liquid droplet ejection heads 7. Itfollows that the number of the function liquid droplet ejection heads 7and the number of the rows, as well as the arrangement pattern may bearbitrarily selected.

[0156] The sub-carriage 41 is made up of: a main body plate 44 which issubstantially square in shape and partly notched; a pair of left andright standard or reference pins 45, 45 which are provided in anintermediate position as seen in the long side of the main body plate44; a pair of left and right supporting members 46, 46 which areattached to both the long sides of the main body plate 44; and a pair ofleft and right handles 47, 47 which are provided at an end of each ofthe supporting members 46. The left and right handles 47, 47 serve asmembers for holding the head unit 26 when an assembled head unit 26, forexample, is mounted onto the above-described liquid droplet ejectionapparatus 10. The left and right supporting members 46, 46 serve asmembers for fixing the sub-carriage 41 to the setting portion of theliquid droplet ejection apparatus 10 (details thereof will be describedhereinafter). Further, the pair of the standard pins 45, 45 serve as thestandard for positioning (positionally recognizing) the sub-carriage(head unit 26), based on the image recognition, in the X-axis, Y-axis,and the Θ-axis directions.

[0157] The sub-carriage 41 is further provided with a piping joint 49 ata position away from each of the function liquid droplet ejection heads,e.g., at an end portion on the side of the handle 47 of the sub-carriage41. The piping joint 49 serves the purpose of detachably connecting:that piping material 48 a on the side of the head (head-side pipingmaterial 48 a) which is communicated with each of the function liquiddroplet ejection heads through a piping adapter 48; and that pipingmaterial on the side of the apparatus (apparatus-side piping material)which is communicated with a liquid supply tank 126 (to be describedhereinafter) for the liquid supply and recovery apparatus 13.

[0158] As shown in FIGS. 24A and 24B, the piping joint 49 is providedwith an oblong plate 491 which is fixed to an end on the side of thehandle 47 in the sub-carriage 41 through a bracket 490. Twelve sockets492 in total in the upper and lower rows are fixed by fitting to theplate 491. One end of each of the sockets 492 has connected thereto eachof the head-side piping material 48 a through a piping coupling 493. Theother end of each of the sockets 492 has formed therein a plug hole 492a into which a plug 494 is detachably fitted (i.e., fitted in a mannercapable of being plugged into and plugged out of position).

[0159] The apparatus-side piping material is connected to the plugs 494through elbow pipes 495. In this manner, by simply plugging each of theplugs 494 into, and out of, each of the sockets 492, the apparatus-sidepiping material can be connected to, or detached from, the head-sidepiping material 48 a. Even if there occurs a liquid run (running orflowing or dripping of the liquid) at the time of separating the pipingmaterial, there is no possibility of the running liquid's gettingadhered to the connectors 66 (see FIG. 25A) of the function liquiddroplet ejection heads 7 because the piping joint 49 is away from thefunction liquid droplet ejection heads 7. The plugs 494 are preventedfrom being inadvertently pulled out of position due to a stay bar 497which is detachably mounted on the plate 491 through screws 496 on bothends thereof.

[0160] In case there occurs a clearance (or gap) to the plug 494 withinthe plug hole 492 a, the air bubbles through the clearance penetrateinto the function liquid droplet ejection heads 7, resulting in afailure in ejection (or wrong ejection) of the liquid droplet. As asolution, in this embodiment, the hole bottom surface 492 b of the plughole 492 a is formed into a tapered surface to suit the taper of thefront end of the plug 494 to thereby prevent the clearance fromoccurring. A clearance may occur to a smaller degree between the holebottom surface 492 b and the front end of the plug 494 through adimensional tolerance in the depth of the plug hole 492 a and the lengthof the plug 494. However, since this clearance is directed in a taperedshape in the direction of flow of the liquid that flows out of the plug494, the air bubbles can be easily removed by suction out of theclearance at the step of liquid filling which is carried out when thehead unit 26 is placed in position in the ejection apparatus 1.Therefore, there is no possibility of the air bubbles' getting into thefunction liquid droplet ejection heads 7 through the clearance duringoperation of the ejection apparatus 1.

[0161] In this embodiment, a plurality of, e.g., two O-rings 498 for thepurpose of sealing the plug holes 492 a are attached to the perimeter ofthe plug 494 at an axial distance from each other. The sealing propertybetween the plug 494 and the socket 492 is thus improved.

[0162] Though not illustrated, the sub-carriage 41 is provided, on anupper side of the two rows of the left and right function liquid dropletejection head groups, with a pair of left and right wiring (or cable)connection assemblies to be connected to the function liquid dropletejection heads 7. Each of the wiring connection assemblies is arrangedto be connected by wires (or cables) to the a control apparatus (headdriving unit, not illustrated) of the ejection apparatus 1.

[0163] As shown in FIGS. 25A and 25B, the function liquid dropletejection head 7 is of a so-called dual (twin) construction and is madeup of: a liquid introduction part 61 having dual connection needles 62,62; a dual head substrate 63 which is in communication with a side ofthe liquid introduction part 61; a dual pump part 64 which is incommunication with a lower portion of the liquid introduction part 61;and a nozzle forming plate 65 which is in communication with the pumppart 64. Each of the connection needles 62 has connected thereto theabove-described piping adapter 48. To the base portion of each of theconnection needles 62 there is mounted a filter 62 a for preventingforeign substances from getting into the pump part 64. Flexible flatcables (not illustrated) to be drawn (or pulled out) from the wiringconnection assemblies are connected to the connectors 66, 66 of the headsubstrate 63.

[0164] A rectangular head main body 60 which projects toward the backside of the sub-carriage 41 is constituted by the pump part 64 and thenozzle forming plate 65. A nozzle forming surface 67 of the nozzleforming plate 65 has parallelly disposed therein two rows of nozzlearrays 69, 69, each row having a multiplicity of ejection nozzles 68.The piping adapters 48 are arranged such that two of them arerespectively disposed for each of the function liquid droplet dischargeheads 7 in correspondence to the dual connection needles 62, 62.Therefore, the head-side piping material 48 a to be connected to each ofthe sockets 492 of the piping joint 49 is connected to the two pipingadapters 48, 48 through a Y-shaped coupling 49.

[0165] A description will now be made in sequence about the otherconstituting apparatuses of the liquid droplet ejection apparatus 10 andthe auxiliary apparatus 11.

[0166]FIGS. 26 through 29 show the supporting rack 21 and the stone base22 on which is mounted the X-axis table. As shown in these figures, thesupporting rack 21 is constituted by assembling L-shaped structuralmembers, or the like, into a rectangle, and has a plurality of (nine)supporting legs 71 with adjusting bolts which are distributed in a lowerpart thereof. On an upper part of the supporting rack 21 there areprovided, in a manner extending sidewise and two in number for eachside, a plurality of (eight) fixing members 72 for fixing the stone base22 at the time of movement such as transportation, or the like. Each ofthe fixing members 72 is formed into an L shape like a bracket and isfixed, at its base end, to the upper side face of the supporting rack 21and is brought, at its front end, into contact with the lower side faceof the stone base 22 through the adjusting bolts 73. The stone base 22is placed in position on the supporting rack 21 in an untied state. Whenthe stone base 22 is transported, it is fixed by the fixing members 72to the supporting rack 21 in a manner immovable in the X-axis directionand in the Y-axis direction (i.e., back-and-forth and sidewisedirections) relative to the supporting rack 21.

[0167] The stone base 22 is to support the X-axis table 23 and theY-axis table 24, both being for moving the function liquid dropletejection heads 7 at a high accuracy, so as not to give rise todeviations in accuracy (especially in respect of the degree of flatness)due to environmental conditions, vibrations, or the like. It isconstituted by a solid stone material which is rectangular in plan view.The stone base 22 is provided at its lower part with three mainsupporting legs 75 and six auxiliary legs 76, all with adjusting bolts,for supporting the stone base 22 on the supporting rack 21. The threemain supporting legs 75 support the stone base 22 at three points tothereby secure the degree of parallelism of the surface (also to securethe degree of horizontalness). The six auxiliary legs 76 are to supportthe portions away from the three main supporting legs 75 of the stonebase 22 to thereby keep the stone base 22 from deflecting.

[0168] For this purpose, as schematically shown in FIG. 29, the threemain supporting legs 75, 75, 75 are disposed in a manner to form anisosceles triangle with the two main legs 75 forming the base beingpositioned on that side of the stone base 22 from which the substrate istransported (i.e., on the left side in FIG. 29 and on this side, i.e.,on the side of the viewer of the figure, in FIG. 16). The six auxiliarylegs 76, 76, 76, 76, 76, 76 are evenly distributed in such a manner thatthey constitute 3×3 in the longitudinal and lateral directions inclusiveof the above-described three main supporting legs 75, 75, 75.

[0169] In this arrangement, the X-axis table 23 is disposed such thatthe axial line thereof coincides with the center line along the longsides of the stone base 22, and the Y-axis table 24 is disposed suchthat the axial line thereof coincides with the center line along theshort sides of the stone base 22. Therefore, the X-axis table 23 isfixed directly to the stone base 22 and the Y-axis table 24 is fixed tothe stone base 22 by four supporting columns 78 through respectivespacer blocks 79. As a result, the Y-axis table 24 is disposed so as tolie above the X-axis table 23 at right angles thereto. Reference numeral80 in FIG. 27 denotes four small blocks for fixing thereto mainsubstrate recognition cameras which are described in detail hereinafter.The main substrate recognition cameras are also fixed to the stone base22.

[0170] As shown in the X-axis moving system in FIGS. 26 through 28 andin the Θ-axis moving system in FIGS. 30 through 32, the X-axis table 23extends along the long sides of the stone base 22 and is made up of: asuction table 81 which sucks the substrate W in position by air suction;a Θ-axis table 82 which supports the suction table 81 (see FIGS. 30through 32); an X-axis air slider 83 which supports the Θ-axis table 82in a manner slidable in the X-axis direction; an X-axis linear motor 84which moves the substrate W on the suction table 81 in the X-axisdirection through the Θ-axis table 82; and an X-axis linear scale 85which is provided in line with the X-axis air slider 83 (see FIGS. 26through 29).

[0171] The X-axis linear motor 84 is positioned on that side of theX-axis air slider 83 from which the head unit 26 is transported, and theX-axis linear scale 85 is positioned on that side of the X-axis airslider 83 on which the auxiliary apparatus 11 is disposed, and theX-axis air slider 83 and the X-axis linear scale 85 are disposed inparallel with each other. The X-axis linear motor 84, the X-axis airslider 83 and the X-axis linear scale 85 are directly supported on thestone base 22. The suction table 81 has connected thereto a vacuum pipe(not illustrated) which is in communication with the above-describedvacuum suction apparatus 15. The substrate W which is set in position bythe air suction is held by suction in order to maintain its flatness.

[0172] The X-axis linear scale 85 has, on the side of the auxiliaryapparatus 11, an X-axis flexible cable bundler 87 in parallel with thelinear scale 84 in a state in which it is contained in a box 88 on thestone base 22. The X-axis flexible cable bundler 87 contains thereinvacuum pipes for the suction table 81, cables for the Θ-axis table 82,or the like, so that they follow the movement of the suction table 81and the Θ-axis table 82 (see FIGS. 27 and 28).

[0173] The X-axis table 23 constituted as described above is operated bythe driving of the X-axis linear motor 84 such that the suction table 81having sucked thereto the substrate W and the Θ-axis table 82 are movedin the X-axis direction guided by the X-axis air slider 83. In thereciprocating movements in the X-axis direction, the relative mainscanning of the function liquid droplet ejection heads 7 is carried outby the forward movement from the side of transportation of the substratetoward the inner side. In addition, based on the result of recognitionby the main substrate recognition camera 90 (to be described in detailhereinafter), the Θ-axis correction (angular correction within thehorizontal plane) of the substrate W is carried out by the Θ-axis table82.

[0174]FIG. 33 shows the main substrate recognition camera. As showntherein, there are disposed a pair of main substrate recognition cameras90, 90 right above the suction table 81 so as to face the position inwhich the substrate is transported (receiving and handover position).The pair of main substrate recognition cameras 90, 90 are arranged tosimultaneously carry out the image-wise recognition (recognition bymeans of an image) of the two reference positions of the substrate.

[0175] As shown in FIGS. 34, 35 and 36, the Y-axis table 24 extendsalong the short sides of the stone base 22 and is made up of: a bridgeplate 91 which suspends the main carriage 25; a pair of Y-axis sliders92, 92 which support the bridge plate 91 on both ends so as to beslidable in the Y-axis direction; a Y-axis linear scale 93 which isprovided in parallel with the Y-axis slider 92; a Y-axis ball screw 94which moves the bridge plate 92 in the Y-axis direction guided by thepair of Y-axis sliders 92, 92; and a Y-axis motor 95 which rotates theY-axis ball screw in one direction and in the opposite direction ofrotation. A pair of Y-axis flexible cable bundlers 96, 96 are disposedin a manner respectively housed in boxes 97, 97.

[0176] The Y-axis motor 95 is constituted by a servo motor. When theY-axis motor 95 rotates in one direction and in the opposite directionof rotation, the bridge plate 91 which is in screwed engagementtherewith through the Y-axis ball screw 94 moves in the Y-axis directionwith the pair of the Y-axis sliders 92, 92 serving as the guides. Inother words, accompanied by the movement of the bridge plate 91 in theY-axis direction, the main carriage 25 moves in the Y-axis direction. Inthe back and forth movements of the main carriage 25 (head unit 26) inthe Y-axis direction, the sub-scanning by the function liquid dropletejection heads 7 is carried out in the forward movement from the homeposition toward the auxiliary apparatus 11.

[0177] On the four supporting columns 78 there are supported thereon amounting-base plate 98 with the moving path portion of the main carriage25 forming a rectangular opening 98 a. On the mounting-base plate 98there are disposed the pair of Y-axis sliders 92, 92 to stand clear ofthe rectangular opening 98 a, and the Y-axis ball screw 94 in parallelwith each other. On a pair of supporting plates 99, 99 which extendoutward from the mounting-base plate 98, there are placed theabove-described pair of Y-axis flexible cable bundlers 96, 96 togetherwith the boxes 97, 97 therefor.

[0178] The Y-axis flexible cable bundler 96 on the side of transportingthe substrate houses therein the cables which are mainly connected tothe head unit 26. The Y-axis flexible cable bundler on the opposite sidehouses therein those pipes for the function liquid droplet which aremainly connected to the head unit 26 (both not illustrated). Thesecables and pipes are connected to the plurality of function liquiddroplet ejection heads 7 in the head unit 26 through the bridge plate91.

[0179] As shown in FIGS. 37 and 38, the main carriage 25 is made up of:a suspending member 101 which is fixed to the bridge plate 91 from thebottom side and which is of I-shape in external appearance; a Θ-axistable 102 which is attached to the lower surface of the suspendingmember 101; and a carriage main body 103 which is attached to the lowersurface of the Θ-axis table 102 in a suspended manner. This suspendingmember 101 faces the rectangular opening 98 a of the mounting-base plate98.

[0180] The carriage main body 103 is made up of: a base plate 104 onwhich the head unit 26 is seated; an arch (portal) member 105 whichsupports the base plate 104 in a suspended manner; a pair of provisionalplacing L-shaped (angular) members 106, 106 which are provided so as toprotrude from one end of the base plate 104; and a stopper plate 107which is provided at the other end of the base plate 104. On an outsideof the stopper plate 107 there are disposed a pair of theabove-described subsidiary substrate recognition cameras 108 whichrecognize the substrate W.

[0181] The base plate 104 has formed therein a rectangular opening 111into which the main body plate 44 of the head unit 26 is loosely fitted.Each left and right opening edge portion 112 of the base plate 104,which forms the rectangular opening 111, is provided with bolt holes113, 113, two penetrating holes 114, 114, and positioning pins 115 whichare used for positioning and fixing the head unit 26.

[0182] Into the main carriage 25 which is constituted as describedabove, the head unit 26 is transported and set in position by holding itwith both the handles 47, 47. Namely, the transported head unit 26 isonce placed on both the provisional placing L-shaped members 106, 106(provisional placing). Then, the pipes which are in communication withthe functional liquid supply and recovery apparatus 13 which is disposedon the bridge plate 91 are connected to the pipe connection assembly 49of the head unit 26, and is also the cables of the control system areconnected to the cable connection assembly 50. Then, by holding both thehandles 47, 47 again, the head unit 26 is pushed forward with both theprovisional placing L-shaped members 106, 106 serving as guides. Thehead unit 26 is thus set in position into the left and right openingedges 112, 112 of the base plate 104.

[0183] A description will now be made about the common machine base 31.As shown in FIGS. 39 through 42, the common machine base 31 is made upof: a machine base main body 121 in which two containing rooms, i.e., alarge containing room 122 a and a small containing room 122 b, areformed with a partition wall therebetween; a movable table 123 which isprovided on the machine base main body 121; a common base 124 which isfixed to the movable table 123; and a tank base 125 which is provided inan end position away from the movable table 123 on the machine base mainbody 121. The common base 124 has mounted thereon the cleaning unit 34and the wiping unit 35. The tank base 125 has mounted thereon a liquidsupply tank 126 for the function liquid supply and recovery apparatus 13which is described in detail hereinafter.

[0184] On a lower surface of the machine base main body 121 there areprovided six supporting legs 128 with adjusting bolts, as well as fourcasters 129. On that side of the machine base main body 121 which lieson the liquid droplet ejection apparatus 10, there are provided a pairof connection brackets 130, 130 for connection to the supporting rack 21of the liquid droplet ejection head 10. According to this arrangement,the liquid droplet ejection apparatus 10 and the auxiliary apparatus 11(common machine base 31) can be integrated, and the auxiliary apparatus11 can be separated and moved depending on necessity.

[0185] The small containing room 122 b of the machine base main body 121contains therein the main portions of the air supply apparatus 14 andthe vacuum suction apparatus 15, and the large containing room 122 acontains therein the tanks, or the like, of the function liquid supplyand recovery apparatus 13. The coupling groups 131 for connection tothese tank groups face the rectangular opening 121 a which is formed inthe upper surface of the end portion of the machine base main body 121(see left end in FIG. 42). A waste liquid pump 152 (to be described indetail hereinafter) is provided in a position near the rectangularopening 121 a.

[0186] The movable table 123 extends along the longitudinal direction ofthe machine base main body 121 and is made up of: a rectangular table133 which supports the common base 124; a pair of movable sliders 134,134 which slidably support the rectangular table 133; a ball screw 135which is disposed between the pair of the movable sliders 134, 134; anda moving motor 136 for rotating the ball screw 135 in one direction andin the opposite direction of rotation. The moving motor 136 is connectedto an end of the ball screw 135 through a coupling 137, and therectangular table 133 is engaged with the ball screw 135 in a screwedmanner through a female spool 138. According to this arrangement, whenthe moving motor 136 is rotated in one direction and in the oppositedirection of rotation, the rectangular table 133 and the common base 124move back and forth in the X-axis direction through the ball screw 135.

[0187] The moving table 123 moves the cleaning unit 34 and the wipingunit 35 which are disposed on the common base 124. When the moving table123 is driven, the head unit 26 is in a position right above thecleaning unit 34 by means of the Y-axis table 24. Once the cleaning unit34 has sucked the function liquid in close contact with the plurality offunction liquid droplet ejection heads 7 of the head unit 26, the nozzleforming surface 67 of each of the function liquid droplet ejection heads7 gets contaminated or stained. Therefore, the wiping unit 35 comesclose to the plurality of function liquid droplet ejection heads 7 bymeans of the moving table 123 and operates to wipe out the contaminationon the nozzle forming surface 67 (details of this operation will bedescribed hereinafter).

[0188] On a side of the moving table 123 there is disposed a flexiblecable bundler 139. This flexible cable bundler 139 is fixed to the uppersurface of the common machine base 31 and the front end thereof is fixedto the common base 124; it contains therein the cables, air pipes,cleaning pipes, pipes for the waste liquid (to be reused), or the like(not illustrated; cleaning is described in detail hereinafter).

[0189] With reference to FIGS. 43 through 46, a description will now bemade about the function liquid supply and recovery apparatus 13. Asshown in the piping diagram in FIG. 43, the function liquid supply andrecovery apparatus 13 is made up of: a function liquid supply system 141which supplies each of the function liquid droplet ejection heads 7 ofthe head unit 26 with the function liquid; a function liquid recoverysystem 142 which recovers the function liquid that has been sucked bythe cleaning unit 34; a cleaning liquid supply system 143 which suppliesthe solvent of the function liquid for the purpose of cleaning; and awaste liquid recovery system 144 which recovers the waste liquid of thefunction liquid from the flushing unit 33.

[0190]FIGS. 44 and 45 show the tank groups which are contained insidethe large containing room 122 a in the common machine base 31. Aplurality of tank groups are mounted on a liquid-proof pan 146 of adrawer type. On the liquid-proof pan 146 there are laterally disposed,as seen from the left in the figure, a cleaning tank 147 for thecleaning liquid supply system 143, a reusing tank 148 for the functionliquid recovery system 142, and a pressurizing tank 149 for the functionliquid supply system 141, which constitute the tank groups. A wasteliquid tank 150, which is formed into a small size, for the waste liquidrecovery system 144 is disposed near the cleaning tank 147 and thereusing tank 148.

[0191] As shown in FIG. 43, the waste liquid tank 150 is connected tothe flushing unit 33 through the waste liquid pump 152 and recovers backto the waste tank 150 the function liquid ejected by each of thefunction liquid droplet ejection heads 7 to the flushing unit 33. Thereusing tank 148 is connected to the suction pump 153 of the cleaningunit 34 and recovers the function liquid as sucked by the suction pump153 from each of the function liquid droplet ejection heads 7. As shownin FIG. 46, the waste liquid pump 152 and a gate valve 154 on anupstream side of the liquid supply tank 126, which is described indetail hereinafter, are fixed to the supporting plate 155 and aremounted, as described hereinabove, on the upper surface of the endportion of the machine base main body 121 (see FIG. 16).

[0192] As shown in FIG. 43, the cleaning tank 147 is connected at itssuction side to the air supply apparatus 14 and is connected at itsdelivery or discharge side to atomizing nozzles (to be described indetail hereinafter) 195 of the cleaning liquid atomizing head of thewiping unit 35. Namely, the cleaning tank 147 supplies the cleaningliquid inside thereof to the cleaning liquid atomizing head 195 underpressure by the compressed air to be introduced from the air supplyapparatus 14. Although the details are described hereinafter, thecleaning liquid ejected out of the cleaning liquid atomizing head 195 isimpregnated into a wiping sheet 182 which is to wipe out the functionliquid droplet ejection heads 7.

[0193] The pressurizing tank 149 has connected thereto a pressurizingpipe 157 which is communicated with the air supply apparatus 14. Thedelivery side of the pressurizing tank 149 is connected to the liquidsupply tank 126 of the function liquid supply system 141. In otherwords, the pressurizing tank 149 is a main tank for the liquid material.The liquid material inside the pressurizing tank 149 is send underpressure to the liquid supply tank 126 by the pressurized air to beintroduced from the air supply apparatus 14.

[0194]FIGS. 47 through 49 show the liquid supply tank 126. The liquidsupply tank 126 is fixed to the tank base 125 and is made up of: arectangular tank main body 161 which is provided with a liquid levelpeep hole 162 on each side and is closed by a flange; a liquid leveldetector 163 which faces both the liquid level peep holes 162, 162 fordetecting the liquid level of the function liquid; a pan 164 on whichthe tank main body 161 is placed; and a tank stand 165 which supportsthe tank main body 161 through the pan 164.

[0195] The tank stand 165 is made up of an attaching plate 167 and twosupporting column-like members 168, 168 which are vertically provided onthe attaching plate 167. It is thus so arranged that the height and thelevel of the tank main body 161 can be finely adjusted by the twosupporting column-like members 168. The (lid of the) upper surface ofthe tank main body 161 has connected thereto a supply pipe 169 which iscommunicated with the pressurizing tank 149. There are also provided sixconnectors 170 a for the pipes or passages (reference numeral 158 inFIG. 43) which are communicated with the head unit 26, and a connector170 b for opening to the open air (outside air).

[0196] The liquid level detector 163 is made up of a high-liquid leveldetector 163 a and a low-liquid level detector 163 b which are disposedat a slight vertical distance from each other. The high-liquid leveldetector 163 a and the low-liquid level detector 163 b are mounted so asto be respectively adjustable in height at the base portion relative tothe tank stand 165. The high-liquid level detector 163 a and thelow-liquid level detector 163 b have a pair of plate-shaped arms 163 c,163 c which extend toward the respective liquid level peep holes 162,162 of the tank main body 161. The pair of the plate-shaped arms 163 c,163 c have on one end thereof a light emitting element 163 d which facesone of the liquid level peep holes 162 and on the other end thereof alight receiving element 163 e which faces the other of the liquid levelpeep holes 162. In other words, a transmission type of liquid levelsensor is constituted by the light emitting element 163 d and the lightreceiving element 163 e.

[0197] On an upstream side of the supply pipe 169 which is connected tothe liquid supply tank 126, there is interposed a gate valve 154 (seeFIGS. 43 and 46). The gate valve 154 is controlled to be opened andclosed by an upper limit level detector 163 a and a lower limit leveldetector 163 b and is adjusted so that the liquid level in the liquidsupply tank 126 always lies between the upper limit level and the lowerlimit level. The liquid supply tank 126 is freed from the pressure onthe side of the pressurizing tank 149 by the venting to the atmosphere.Therefore, the liquid material is supplied to the function liquiddroplet ejection heads 7 by a slight head pressure (e.g., 25 mm±0.5 mm)to be controlled by the adjustment in the above-described liquid level.According to this arrangement, the liquid droplet can be ejected at ahigh accuracy by the pumping operation of the function liquid dropletejection heads 7, i.e., by the pumping drive of a piezoelectric elementinside the pimp part 64. The running of the liquid from the ejectionnozzles 68 of the function liquid droplet ejection heads 7 can thus beprevented.

[0198] As shown in FIG. 43, six liquid supply passages 158 from theliquid supply tank 126 are branched respectively into two, i.e., a totalof twelve, branch passages 158 b through respective T-shaped couplings158 a. Each of these branch passages 158 b is connected as theapparatus-side piping material to each of the twelve sockets 492 for thepiping joints 49 provided in the head unit 26. In addition, a gate valve166 is interposed in each of the branch passages 158 b. It is soarranged that the gate valves 166 can be temporarily closed as describedhereinafter at the liquid filling step.

[0199] A description will now be made about the maintenance apparatus16, in the order of the wiping unit 35, the cleaning unit 34, and theflushing unit 33.

[0200] As sown in FIGS. 50 through 55, the wiping unit 35 is made up ofa rolling unit 171 (see FIGS. 50 through 52) which is independentlyconstituted, and a wipe-out unit 172 (see FIGS. 53 through 55), both ofwhich are disposed on the common base 124 in an abutting positionalrelationship. The rolling unit 171 is disposed on this side of thecommon base 124 and the wipe-out unit 172 is disposed on the other(inner) side of the common base 124, i.e., on the side of the cleaningunit 34.

[0201] The wiping unit 35 of this embodiment has the followingarrangement. Namely, while moving (traveling) a wiping sheet 182 (to bedescribed hereinafter) relative to the head unit 26 which is heldstationary right above the cleaning unit 34, i.e., in the cleaningposition, the wiping unit 35 is moved by the moving table 123 in theX-axis direction, to thereby wipe out the function liquid dropletejection heads 7. For this purpose, the wiping unit 35 is arranged to berolled out of the rolling unit 171 to move around the wipe-out unit 172for wiping operation and is rolled into the rolling unit 171.

[0202] As shown in FIGS. 50 through 52, the rolling unit 171 is made upof: a frame 174 of a cantilever type; an upper feeding reel 175 which isrotatably supported on the frame 174; and a takeup motor 177 whichrotates a takeup reel 176 for the purpose of taking up. The frame 174has a sub-frame 178 which is fixed to an upper side portion thereof.This sub-frame 178 has supported thereon a speed detecting roller 179and an intermediate roller 180 so as to be positioned on a front end ofthe feeding reel 175 in a manner supported on both sides. On a lowerside of these constituent parts, there is disposed a cleaning liquid pan181 for receiving therein the cleaning liquid.

[0203] The feeding reel 175 has inserted therethrough a wiping sheet 182of a rolled shape. The wiping sheet 182 rolled (or fed) out of thefeeding reel 175 is fed to the wiping unit 172 through a speed detectingroller 179 and an intermediate roller 180. Between the takeup reel 176and the takeup motor, there is extended a timing belt 183. The takeupreel takes up the wiping sheet 182 by the rotation of the takeup motor177.

[0204] Though details are given hereinafter, the wiping unit 172 is alsoprovided with a motor (wiping motor 194) which feeds the wiping sheet182. The feeding reel 175 is rotated while being braked so as to actagainst the wiping motor 194. The speed detecting roller 179 is a griproller which is made up of an upper and a lower, i.e., two, freelyrotatable rollers 179 a, 179 b and controls the takeup motor 177 bymeans of a speed detector 185 which is provided thereon. In other words,the feeding reel 175 feeds out the wiping sheet 182 in a state of beingstretched, and the takeup reel 176 rolls up such that the wiping sheet182 does not slacken.

[0205] As shown in FIGS. 53 through 55, the wiping unit 172 is made upof: a pair of left and right stands 191, 191; a base frame 192 which issubstantially U-shaped in cross section and is supported by the pair ofstands 191, 191; a wiping roller 193 which is rotatably supported by thebase frame 192 on both sides thereof; a wiping motor 194 which rotatesthe wiping roller 193; a cleaning liquid spaying head 195 which lies inparallel with the wiping roller 193; and a pair of double-acting type ofair cylinders 196, 196 which move the base frame 192 up and down.

[0206] The pair of stands 191, 191 are made up of stationary standswhich are positioned respectively outside, and movable stands 199 whichare attached to the inside of the stationary stands 198 in a mannerslidable up and down. At the base portion of each of the stationarystands 198, there are vertically disposed the above-described aircylinders 196. A plunger 196 a of each of the air cylinders 196 is fixedto the movable stand 199. By means of the pair of air cylinders 196, 196which are driven at the same time, the base frame 192 and the wipingroller 193, the wiping motor 194, or the like, that are supported on thebase frame 192 are moved up and down.

[0207] The wiping roller 193 is constituted by a grip roller made up ofa driving roller 202 which is coupled to the wiping motor 194 through atiming belt 201, and a driven roller 203 which comes into contact withthe driving roller 202 with the wiping sheet 182 sandwichedtherebetween. The driving roller 202 is constituted by a rubber rolleraround which is wound a rubber having resiliency or flexibility, e.g.,at the core portion. The wiping sheet to be wound therearound is urgedtoward the nozzle forming surface 67 of the function liquid dropletejection heads 7.

[0208] The cleaning liquid atomizing head 195 lies close to the wipingroller 193 (driving roller 202) and sprays the wiping sheet 182, to befed from the intermediate roller 180, with the cleaning liquid which isconstituted by a solvent, or the like, of the function liquid. For thispurpose, the front surface of the cleaning liquid atomizing head 195,i.e., the side of the wiping roller 193, is laterally provided with aplurality of atomizing nozzles 204 to suit the width of the wiping sheet182. The back surface of the cleaning liquid atomizing head 195 isprovided with a plurality of connectors 205 for connection of the pipeswhich are in communication with the cleaning tank 147.

[0209] The wiping sheet 182 which has been sprayed with the cleaningliquid is impregnated with the cleaning liquid and is arranged to facethe function liquid droplet ejection heads 7 to wipe them out. Below thewiping roller 193, a cleaning liquid pan is also provided in the baseframe 192 so that, together with the cleaning liquid pan 181 of therolling unit 171, the cleaning liquid to be dropping from the wipingsheet 182 is received therein.

[0210] With reference to the schematic diagram in FIG. 56, a briefdescription will now be made about a series of wiping operations. Oncethe cleaning of the head unit 26 has been finished, the moving table 123is driven, and the wiping unit 35 is moved forward to thereby make itclose enough to the head unit 26. Once the wiping roller 193 has movedto the neighborhood of the function liquid droplet ejection heads 7, themoving table 123 is stopped. The air cylinders 196, 196 are driven tomove upward the wiping roller 193 so as to urge or bring it into contactwith the function liquid droplet ejection heads 7.

[0211] Then, the takeup motor 177 and the wiping motor 194 are driven tothereby feed the wiping sheet 182 for wiping operation, and theatomizing of the cleaning liquid is started. At the same time, themoving table 123 is moved once again. While feeding the wiping sheet182, the wiping roller 193 is advanced so that the lower surface of theplurality of the function liquid droplet ejection heads 7 can be wiped.Once the wiping operation has been finished, the feeding of the wipingsheet 182 is stopped and the wiping roller 193 is lowered, and thewiping unit 35 is returned to the original position by the moving table123.

[0212] With reference to FIGS. 57 through 60, a description will now bemade about the cleaning unit 34. The cleaning unit 34 is made up of: acap unit 211 in which twelve caps 212 corresponding to the twelvefunction liquid droplet ejection heads 7 are disposed in a cap base 213;a supporting member 214 which supports the cap unit 211; and anelevating mechanism 215 which moves up and down the cap unit 211 throughthe supporting member 214.

[0213] As shown in FIG. 43, a suction passage (pipe) 216 which iscommunicated with the reusing tank 148 with a suction pump 153interposed therein is branched into twelve branch passages 216 b througha header pipe 216 a and each of these branch passages 216 b is connectedto each of the caps 212. Each of the branch passages 216 b is providedwith a liquid sensor 217, a pressure sensor 218, and a gate valve 219 asseen from the side of the caps 212.

[0214] Twelve caps 212 are fixed to the cap base 213 in the same arrayand in the same inclination as those of the twelve function liquiddroplet ejection heads 7. As shown in FIG. 61, each of the caps 212 ismade up of a cap main body 220 and a cap holder 221. The cap main body220 is held by the cap holder 220 in a state of being urged upward bytwo springs 222, 222 and is also slightly movable up and down. The capbase 213 has formed therein twelve mounting openings 224 correspondingto the twelve caps 212, and has formed therein twelve shallow grooves225 in a manner to enclose the mounting openings 224. Each of the caps212 is screwed to the portions of the shallow grooves 225 in a state inwhich the lower part thereof is inserted into the mounting opening 224and in which the cap holder 221 is set in position in the shallow groove225 (see FIG. 60).

[0215] On an upper surface of each of the cap main bodies 220, there isformed a recessed portion 220 a which encloses the two rows of nozzlearrays of the liquid droplet ejection heads 7. Around the perimeter ofthe recessed portion 220 a there is attached a sealing packing 227, andan absorbent member 228 is laid down on the bottom part by means of astay frame 228 a. On the bottom part of the recessed portion 220 thereis formed a small hole 229. This small hole 229 is in communication withan L-shaped coupling 230 which is connected to each of the branchpassages 216 b. When the liquid material is sucked, the sealing packing227 is urged against the nozzle forming surface 67 of the functionliquid droplet ejection heads 7 to thereby seal the nozzle formingsurface 67 in a manner to enclose the two rows of the ejection nozzlegroups.

[0216] Each of the caps 212 is further provided with an open air ventvalve 231 which opens the recessed portion 220 a to the atmosphere onthe bottom side thereof. The open air vent valve 231 is urged toward theupper closing side by means of a spring 231 a. At the final stage ofsuction operation of the liquid, the open air vent valve 231 is pulledopen, whereby the liquid material that has been impregnated into theabsorbent member 228 can be sucked. In the figure, reference numeral 231b denotes an operating part of the open air vent valve 231.

[0217] The supporting member 214 is provided with a supporting membermain body 242 which has a supporting plate 241 for supporting the capunit 211 on an upper end thereof, and a stand 243 which supports thesupporting member main body 242 in a manner movable up and down. To thelower surface on longitudinal both sides of the supporting plate 241,there are fixed a pair of air cylinders 244, 244. There is provided anoperating plate 245 which is moved up and down by the pair of aircylinders 244, 244. On the operating plate 245 there is mounted a hook245 a which is engaged with the operating part 231 b of the open airvent valve 231. In this manner, the open air vent valve 232 is opened orclosed by the pair of air cylinders 244, 244 through the operating plate245.

[0218] The lifting mechanism 215 is made up of a lower lifting cylinder246 which is vertically provided on the base part 243 a of the stand243, and an upper lifting cylinder 247 which is vertically provided onthe plate 248 to be moved up and down by the cylinder 246. The pistonrod of the upper lifting cylinder 247 is connected to the supportingplate 241. The strokes of both the lifting cylinders 246, 247 aredifferent from each other. As a result, by selecting one of the liftingcylinders 246, 147, the lifting position of the cap unit 211 can beswitched between a relatively high first position and a relatively lowsecond position.

[0219] The cap unit 211 has the following arrangement to prevent thefunction liquid droplet ejection heads 7 from coming into contact withthe caps 212 when the head unit 26 is moved to a cleaning position whichfaces right above the cap unit 211. The arrangement is that the cap unit211 is in a standby state at the lower end position which is set so asto keep a clearance of several millimeters (mm) between the sealingpacking 227 of the caps 212 and the nozzle forming surface 67 of thefunction liquid droplet ejection heads 7. As a result of upward movementto the first position, the sealing packing 227 of the caps 212 is causedto be in intimate contact with the nozzle forming surface 67 of thefunction liquid droplet ejection heads 7. At the second position, asmall clearance (e.g., about 0.5 mm) is secured between the sealingpacking 227 of the caps 212 and the nozzle forming surface 67 of thefunction liquid droplet ejection heads 7. In this embodiment, anarrangement is made that the cap unit 211 is moved upward to the firstposition by the lower lifting cylinder 246 and to the second position bythe upper lifting cylinder 247. It may, however, be so arranged that theupward movements to the first position and to the second position arecarried out by the cylinders that are opposite to the above-describedones.

[0220] The cleaning unit 34 thus constituted is moved by the movingtable 123 into a position in which it crosses the moving locus in theY-axis direction of the head unit 26. The head unit 26, on the otherhand, is moved by the Y-axis table 24 to a cleaning position which facesright above the cleaning unit 34 (cap unit 211). Then, by the operationof the lower lifting cylinder 246 of the lifting mechanism 215, the capunit 211 moves upward to the first position so that the twelve caps 212are urged from the lower side toward the twelve function liquid dropletejection heads 7 of the head unit 26. In each of the caps 212 which hasbeen urged toward each of the function liquid droplet ejection heads 7,the cap main body 220 slightly sinks against the two own springs 222,222. As a result, the sealing packing 227 of the cap main body 220 isbrought into intimate contact with the nozzle forming surface 67 of thefunction liquid droplet ejection heads 7.

[0221] Subsequently, the suction pump 153 is driven and the gate valve219 which is interposed in each of the suction branch passages 216 b isopened to thereby suck the liquid material from all of the nozzles 68 ofeach of the function liquid droplet ejection heads 7 through each of thecaps 212. Then, the open air vent valve 231 is opened right before thecompletion of the suction operation, and the gate valve 219 isthereafter closed to complete the suction operation. Once the suctionoperation has been finished, the cap unit 211 is lowered to the lowerend position. During the suction operation, monitoring is made to seewhether the poor suction (or suction failure) has occurred or not toeach of the caps 212 based on a signal from the pressure sensor 218which is disposed in each of the suction branch passages 216 b. Duringthe safe keeping (or holding for stand by), or the like, of the headswhile the apparatus operation is stopped, the cap unit 211 is lifted tothe first position to thereby seal each of the caps 212 with each of thefunction liquid droplet ejection heads 7, whereby a safe keeping stateis secured.

[0222] First, with reference to FIGS. 62 and 63, a description will bemade about the flushing unit 33. This flushing unit 33 is disposed onthe box 88 of the X-axis flexible cable bundler 87 (see FIG. 30). Theflushing unit 33 is made up of: a slide base 251 which is fixed to theX-axis flexible cable bundler 87; a long plate-shaped slider 252 whichis provided in a retractable manner on the slide base 251; a pair offlushing boxes 253, 253 which are fixed to both end portions of theslider 252; and a pair of function liquid absorbing materials 254, 254which are laid out inside each of the flushing boxes 253.

[0223] The pair of the flushing boxes 253, 253 have widths correspondingto each of the function liquid droplet ejection head groups 7 a of thehead unit 26 and have lengths corresponding to the movable range in thedirection of sub-scanning of each of the function liquid dropletejection head groups 7 a, thereby being formed in an elongated shape.These pair of flushing boxes 253, 253 extend at right angles from theslider 252 to the upper side of the X-axis table 23 and are disposed ina manner to sandwich the suction table 81. At the central bottom surfaceof each of the flushing boxes 253, 253 there is attached a draincoupling 256 which constitutes a drain port. The drain pipe (notillustrated) which is connected to this drain coupling 256 is connectedto the waste liquid tank 150 through the X-axis flexible cable bundler87.

[0224] The slider 252 has fixed thereto a pair of mounting pieces 257,257 of the X-axis table 23. The mounting pieces 257, 257 are positionedbetween the pair of flushing boxes 253, 253 and extend toward the Θ-axistable 82. The front end portions of these pair of mounting pieces 257,257 are fixed to the base portion of the Θ-axis table 82. In otherwords, the pair of the flushing boxes 253, 253 are arranged to bemovable together with the Θ-axis table 82 through the slide base 251.

[0225] In the flushing unit 33 as constructed above, when the flushingunit 33 moves forward together with the Θ-axis table 82 as shown in FIG.30, the right side flushing box 253 as shown therein passes first underthe head unit 26. At this time, the plurality of (twelve) functionliquid droplet ejection heads 7 carry out flushing operation insequence, and the head unit 26 transfers to the ordinary liquid dropletejection operation. Similarly, when the flushing unit 33 moves forward,the left side flushing box 253 first passes right under the head. Atthis time, the plurality of function liquid droplet ejection heads 7carry out flushing operation, and the head unit 26 transfers to theordinary liquid droplet ejection operation. In this manner, the flushingoperation is appropriately carried out while the head unit 26 moves backand forth for the main scanning. Therefore, the head unit 26, or thelike, does not move exclusively for the purpose of the flushingoperation, and the flushing thus does not influence the tact time.

[0226] When the ejection of the droplet is suspended for a certainperiod of time, e.g., when the substrate W is carried into, or taken outof, the ejection apparatus 1, the flushing must be carried out.Therefore, when the ejection is held in abeyance for a certain period oftime, the head unit 26 is moved to the cleaning position which facesright above the cap unit 211 to thereby carry out the flushing from eachof the function liquid droplet ejection heads 7 to each of the caps 212.In this case, when the cap unit 211 is present in the lower endposition, part of the ejected liquid from the function liquid dropletejection heads 7 will be spread outside in a misty state through theclearance between the function liquid droplet ejection heads 7 and thecaps 212. As a solution, the cap unit 211 is moved upward to the secondposition by the upper lifting cylinder 247, whereby the flushing iscarried out in this state.

[0227] According to this arrangement, the clearance between the functionliquid droplet ejection heads 7 and the caps 21 becomes slight (orsmall), whereby the outward running or splashing of the liquid ejectedfrom the function liquid droplet ejection heads 7 can be prevented. Inthis case, if the suction force from the suction pump 153 is kept to beoperated on the caps 212, the outward slashing of the ejected liquid canbe more effectively prevented. It is considered to carry out theflushing operation while the caps 212 are kept in close contact with thenozzle forming surface 67 of the function liquid droplet ejection heads7. However, if the caps 212 are brought into intimate contact with thenozzle forming surface 67, the nozzle forming surface 67 gets stained.This idea is, however, not practical because it becomes necessary tocarry out the wiping of the nozzle forming surface 67 after the flushingwork.

[0228] When a new head unit 26 has been introduced into the ejectionunit 1, the flow passages inside the heads of the function liquiddroplet ejection heads 7 are empty. Therefore, it is necessary, beforestarting the ejection work of the liquid droplet, to fill the flowpassages inside the heads with the liquid material. In this case, sincethe supply of the liquid material from the liquid supply tank 126 iscarried out only by the slight or small head pressure, suction becomesnecessary to fill the flow passages inside the heads with the liquidmaterial. Therefore, in filling the liquid droplet, the followingoperations are carried out. Namely, the head unit 26 is moved to thecleaning position. The cap unit 211 is lifted to the first position tothereby bring each of the caps 212 into intimate contact with the nozzleforming surface 67 of each of the function liquid droplet ejection heads7. The liquid material inside the liquid supply tank 126 is then causedto be filled into the flow passage inside the head of each of thefunction liquid droplet ejection heads 7 by means of that suction forcefrom the suction pump 153 which is operated through each of the caps212. However, even if the suction operation is carried out by the caps212, the flow speed of the liquid in the flow passages inside the headslowers and, consequently, the air bubbles cannot successfully be removedout of the flow passages inside the heads. This will cause poorejection, or failure in ejection, of the liquid droplet from the flowpassages inside the heads. Particularly, the air bubbles are likely tostay in the filter 62 a which is disposed at the bottom of theconnection needles 62 of the function liquid droplet ejection heads 7.

[0229] As a solution, in this embodiment, the gate valve 166 isinterposed in each of the branch passages 158 b for liquid supply, andthe liquid sensor 217 is disposed in each of the branch passages 216 bfor suction as described hereinabove. After starting the liquid filling(or charging), the liquid material is sucked up to the caps 212 and,once this state has been detected by the liquid sensor 217, the gatevalves 166 are temporarily closed while continuing the suction by thecaps 212. According to this operation, the pressure in the flow passagesinside the heads is reduced during the closing of the gate valves 166.With the subsequent opening of the gate valves 166, the liquid materialflows suddenly so that the flow speed of the liquid material in the flowpassages inside the heads increases, with the result that the airbubbles are efficiently discharged out of the flow passages inside theheads. According to experiments, the flow speed of about 10 mm/sec.before closing the gate valves has sharply increased to 200-2000 mm/sec.when the gate valves 166 are opened after temporarily closing them.

[0230] The higher the rate of filling the liquid into the flow passagesinside the heads is before closing the gate valves 166, the moreefficiently the pressure inside the flow passages inside the heads canbe reduced. When the liquid material has reached the liquid sensor 217,the flow passages inside the heads are substantially completely filledwith the liquid material. By using the liquid sensors 217, the timing ofclosing the gate valves 166 can adequately be automatically controlled.In addition, by providing each of the branch passages 158 b, 216 b forliquid supply and for liquid suction, respectively, with the gate valve166 and the liquid sensor 217, the gate valves 166 can be separately orindependently closed at a suitable timing for each of the liquidfunction droplet ejection heads 7 even if fluctuations occur in theinitial ratio of liquid filling into the respective function liquiddroplet ejection heads 7.

[0231] The smaller the length of the flow passages between the gatevalves 166 and the function liquid droplet ejection heads 7, the higherthe efficiency of pressure reduction after the valve closing, and thesmaller the amount of liquid consumption at the time of filling. Here,if the gate valves 166 are mounted on a portion which moves integrallywith the main carriage 25, there is no need of securing slacking for thepurpose of following the movement of the head unit 26 to be held on themain carriage 25, the slacking being provided in the passage portionbetween the gate valves 166 and the function liquid droplet ejectionheads 7. This shortens the length of the flow passages. Therefore, inthis embodiment, the gate valves 166 are mounted on the bridge plate 91which suspends the main carriage 25. Details are shown in FIGS. 64 and65. Twelve gate valves 166 are mounted, six each, on two stages of theupper stage and the lower stage on a stand 261 which is fixed to thebridge plate 91.

[0232] Six T-shaped couplings 158 a and six grounding couplings 158 care disposed on an upper plate 262 of the stand 261 which covers theplace of mounting the gate valves 166. Six liquid supply passages(tubes) 158 which are in communication with the liquid supply tank 126are connected to the inwardly faced connecting ports of the T-shapedcouplings 158 a respectively through the grounding couplings 158 c-.Upstream portions 158 b ₁ of these six branch passages 158 b which areconnected to the downwardly faced connecting ports of the T-shapedcouplings 158 a are connected to inlet ports 166 a of the upper-stagesix gate valves 166. Upstream portions 158 b ₁ of the remaining sixbranch passages 158 b which are connected to the outwardly facedconnecting ports of the T-shaped couplings 158 a are connected to inletports of the lower-stage six gate valves 166.

[0233] Twelve pipe couplings 158 d are disposed on a lower plate 263 ofthe stand 261 through brackets 264. Intermediate portions 158 b ₂ of thetwelve branch passages 158 b which are connected to the discharge portsof the total of twelve upper-stage and lower-stage gate valves arerespectively connected to one end of the pipe couplings 158 d.Downstream portions 158 b ₃ of the branch passages 158 b which are theapparatus-side piping material to be connected to the sockets 492 of thepiping joint 49 in the head unit 26 are connected to the other end ofthe piping joints 158 d. The stand 261 is provided with a manifold 265for supplying the head unit 26 with the liquid without passing throughthe gate valve 166.

[0234] A description has so far been made about the apparatus formanufacturing an organic EL device. This invention can also be appliedto the ejection apparatus which is used for manufacturing other productssuch as color filters for the liquid crystal display device, or thelike, to be manufactured by a liquid droplet ejection method.

[0235] For example, in the method of manufacturing a color filter for aliquid crystal display device, filter materials of red color (R), greencolor (G) and blue color (B) are introduced into a plurality of functionliquid droplet ejection heads 7, a plurality of function liquid dropletejection heads 7 are operated for the main scanning and subsidiaryscanning, and the filter materials are selectively ejected, to therebyform a multiplicity of filter elements on a substrate. In addition, anovercoat layer may be formed in a manner similar to the above in orderto coat the multiplicity of filter elements.

[0236] Similarly, the function liquid droplet ejection apparatus 10 ofthis embodiment may also be applied to the method of manufacturing anelectron emission device, the method of manufacturing a PDP device, themethod of manufacturing an electrophoretic display device, or the like.

[0237] In the method of manufacturing an electron emission device,fluorescent materials of red color (R), green color (G) and blue color(B) are introduced into a plurality of function liquid droplet ejectionheads 7, a plurality of function liquid droplet ejection heads 7 areoperated for the main scanning and subsidiary scanning, and thefluorescent materials are selectively ejected, to thereby form amultiplicity of fluorescent members on an electrode. The electronemission device is a generic term to include the idea of field emissiondisplay (FED) device.

[0238] In the method of manufacturing a PDP device, fluorescentmaterials of red color (R), green color (G) and blue color (B) areintroduced into a plurality of function liquid droplet ejection heads 7,a plurality of function liquid droplet ejection heads 7 are operated forthe main scanning and subsidiary scanning, and the fluorescent materialsare selectively ejected, to thereby form fluorescent members in amultiplicity of recessed portions on a substrate.

[0239] In the method of manufacturing an electrophoretic display device,materials for electrophoretic members of respective colors areintroduced into a plurality of function liquid droplet ejection heads 7,a plurality of function liquid droplet ejection heads 7 are operated forthe main scanning and subsidiary scanning, and the ink materials areselectively ejected, to thereby form electrophoretic members in amultiplicity of recessed portions on an electrode. The electrophoreticmembers which are made of electrically charged particles and pigmentsare preferably enclosed in microcapsules.

[0240] The function liquid droplet ejection apparatus 10 of thisembodiment, on the other hand, can be applied to the method of forming aspacer, the method of forming a metallic wiring, the method of forming alens, a method of forming a resist and a method of forming a lightdiffusion member, or the like.

[0241] In the method of forming a spacer, a multiplicity of particulatespacers are formed to constitute a minute cell gap between twosubstrates. Materials which are made by dispersing the particulatematerials to constitute the spacers in a liquid and are formulated intoa liquid state are introduced into a plurality of function liquiddroplet ejection heads 7, the function liquid droplet ejection heads 7are operated for main scanning and subsidiary scanning, and theparticulate materials are selectively ejected to thereby form spacers onat least one of the substrates. This method is also useful inconstituting cell gaps between two substrates in the above-describedliquid crystal display device and electrophoretic display device. It canalso be applied to the method of manufacturing a semiconductor whichrequires this kind of minute gaps.

[0242] In the method of forming metallic wiring, a liquid metallicmaterial is introduced into a plurality of function liquid dropletejection heads 7, the plurality of function liquid droplet ejectionheads 7 are operated for main scanning and subsidiary scanning, and theliquid metallic wiring material is selectively ejected onto thesubstrate. For example, this method can be applied, e.g., to themetallic wiring to connect a driver and each of the electrodes in theabove-described liquid crystal display device, and to the metallicwiring to connect thin film transistors (TFT) and each of the electrodesin the above-described organic EL device. It can also be applied to theart of manufacturing ordinary semiconductors aside from this kind offlat display devices, or the like.

[0243] In the method of forming a lens, a lens material is introducedinto a plurality of function liquid droplet ejection head 7, theplurality of function liquid droplet ejection heads 7 are operated formain scanning and subsidiary scanning, and the lens material isselectively ejected to thereby form a multiplicity of microlenses on atransparent substrate. For example, it can be applied as a device forbeam focusing in the above-described FED device. In addition, it canalso be applicable to various kinds of optical devices.

[0244] In the method of forming a resist, a resist material isintroduced into a plurality of function liquid droplet ejection heads 7,the plurality of function liquid droplet ejection heads 7 are operatedfor main scanning and subsidiary scanning, and the resist material isselectively ejected to thereby form a resist of an arbitrary shape on asubstrate. For example, the method can be widely applied to the formingof banks in the above-described various display devices, as well as tothe coating of photoresist in the photolithography which constitutes themain part of the semiconductor manufacturing art.

[0245] In the method of forming an light diffusion member, amultiplicity of light diffusion members are formed on a substrate, inwhich a light diffusion material is introduced into a plurality offunction liquid droplet ejection heads 7, the plurality of functionliquid droplet ejection heads 7 are operated for main scanning andsubsidiary scanning, and the light diffusion material is selectivelyejected to thereby form a multiplicity of light diffusion members. Thismethod is also applicable to various kinds of optical devices.

[0246] As described hereinabove, according to the method of filling theliquid into the function liquid droplet ejection head and the ejectionapparatus, the flow speed of the liquid at the time of filling (orcharging) the liquid into the function liquid droplet ejection head canbe increased. As a result, the air bubbles can be efficiently removedout of the fluid passage inside the function liquid droplet ejectionhead and the number of suction at the time of filling the liquid can beminimized. The work efficiency can thus be improved and the workabilitycan be improved.

[0247] On the other hand, according to the various kinds ofmanufacturing methods according to this invention such as the method ofmanufacturing the LCD device, the method of manufacturing the organic ELdevice, or the like, the initial charging or filling of the functionliquid into the function liquid droplet ejection head can be quickly andsmoothly carried out, thereby improving the reliability of themanufacturing methods.

What is claimed is:
 1. A method of filling a liquid into a flow passageinside a function liquid droplet ejection head having an ejection nozzleformed in a nozzle forming surface of a head main body, comprising:bringing a cap connected to a suction pump into intimate contact withsaid nozzle forming surface; and filling a liquid of a liquid supplytank connected to said function liquid ejection head into said flowpassage inside said function liquid droplet ejection head, wherein aliquid supply passage between said function liquid droplet ejection headand said liquid supply tank is temporarily closed in a course of fillingthe liquid into said flow passage inside said function liquid dropletejection head while maintaining suction by said cap.
 2. The methodaccording to claim 1, wherein said closing of said liquid supply passageis carried into effect when the liquid inside said liquid supply tankhas been sucked at least up to said cap.
 3. An ejection apparatushaving: a carriage which moves relative to a workpiece; a functionliquid droplet ejection head which is held by said carriage and which isprovided with an ejection nozzle formed in a nozzle forming surface of ahead main body, said function liquid droplet ejection head ejectingdroplets from said ejection nozzle to the workpiece while carrying out arelative movement between said carriage and the workpiece; a liquidsupply tank which is connected to said function liquid droplet ejectionhead; a cap unit which is disposed in a position away from the workpieceand which is provided, in a position corresponding to said functionliquid droplet ejection head, with a cap which is connected to a suctionpump and is brought into intimate contact with the nozzle formingsurface of said function liquid droplet ejection head, in a state inwhich said carriage is moved to a position facing said cap unit, so thatthe liquid of said liquid supply tank is filled into a flow passageinside said function liquid droplet ejection head by a suction force tobe operated upon through said cap, said apparatus comprising: a gatevalve interposed in said liquid supply passage between said functionliquid droplet ejection head and said liquid supply tank, wherein saidgate valve is temporarily closed in a course of filling the liquid intosaid flow passage inside said function liquid droplet ejection headwhile maintaining suction by said cap.
 4. The apparatus according toclaim 3, further comprising a liquid sensor interposed in a suctionpassage between said cap and said suction pump, wherein the temporaryclosing of said gate valve is carried out when, after starting theliquid filling into said flow passage inside said function liquiddroplet ejection head, the liquid has been detected by said liquidsensor.
 5. The apparatus according to claim 4, wherein said carriagefurther comprises a head unit which is made up of a sub-carriage and aplurality of function liquid droplet ejection heads mounted on saidsub-carriage, and wherein said cap is provided in a plurality of numbersto correspond to said plurality of function liquid droplet ejectionheads, wherein said gate valve is interposed in each of branch passagesof said liquid supply passage, each of said branch passages beingconnected by branching to each of said function liquid droplet ejectionheads, wherein said liquid sensor is provided in each of said branchpassages of said suction passages, each of said suction passages beingconnected to each of said caps, and wherein each of said gate valves isclosed when the liquid is detected by each of said liquid sensors. 6.The apparatus according to claim 3, wherein said gate valve is mountedon a portion which moves integrally with said carriage.
 7. A method ofmanufacturing a liquid crystal display device in which a filter elementis formed on a substrate of a color filter by using the ejectionapparatus as set forth in claim 3, said method comprising the steps of:introducing a filter material into said function liquid droplet ejectionhead; carrying out a relative scanning between said function liquiddroplet ejection head and the substrate; and selectively ejecting thefilter material to form the filter element.
 8. A method of manufacturingan organic EL device in which an EL light emitting layer is formed on apixel on a substrate by using the ejection apparatus as set forth inclaim 3, said method comprising the steps of: introducing a lightemitting material into said function liquid droplet ejection head;carrying out a relative scanning between said function liquid dropletejection head and the substrate; and selectively ejecting the lightemitting material to form the EL light emitting layer.
 9. A method ofmanufacturing an electron emission device in which a fluorescent memberis formed on an electrode by using the ejection apparatus as set forthin claim 3, said method comprising the steps of: introducing afluorescent material into said function liquid droplet ejection head;carrying out a relative scanning between said function liquid dropletejection head and the substrate; and selectively ejecting thefluorescent material to form the fluorescent member.
 10. A method ofmanufacturing a PDP device in which a fluorescent member is formed on arecessed portion on a back substrate by using the ejection apparatus asset forth in claim 3, said method comprising the steps of: introducing afluorescent material into said function liquid droplet ejection head;carrying out a relative scanning between said function liquid dropletejection head and the substrate; and selectively ejecting thefluorescent material to form the fluorescent member.
 11. A method ofmanufacturing an electrophoretic display device in which anelectrophoretic member is formed on a recessed portion on an electrodeby using the ejection apparatus as set forth in claim 3, said methodcomprising the steps of: introducing an electrophoretic material intosaid function liquid droplet ejection head; carrying out a relativescanning between said function liquid droplet ejection head and thesubstrate; and selectively ejecting the electrophoretic material to formthe electrophoretic member.
 12. A method of manufacturing a color filterin which a filter element is arrayed on a substrate by using theejection apparatus as set forth in claim 3, said method comprising thesteps of: introducing a filter material into said function liquiddroplet ejection head; carrying out a relative scanning between saidfunction liquid droplet ejection head and the substrate; and selectivelyejecting the filter material to form the filter element.
 13. The methodof forming a color filter according to claim 12 in which an overcoatlayer is coated on said filter element, further comprising the steps of:introducing a translucent coating material into said function liquiddroplet ejection head after the filter element has been formed; carryingout a relative scanning between said function liquid droplet ejectionhead and the substrate; and selectively ejecting the coating material toform the overcoat layer.
 14. A method of manufacturing an organic EL inwhich pixel inclusive of an EL light emitting layer is arrayed on asubstrate by using the ejection apparatus as set forth in claim 3, saidmethod comprising the steps of: introducing the light emitting materialinto said function liquid droplet ejection head; carrying out a relativescanning between said function liquid droplet ejection head and thesubstrate; and selectively ejecting the light emitting material to formthe EL organic layer.
 15. The method of manufacturing an organic ELaccording to claim 14 in which a pixel electrode is formed to correspondthe EL light emitting layer, said method further comprising the stepsof: introducing the liquid electrode material into said function liquiddroplet ejection head; carrying out a relative scanning between saidfunction liquid droplet ejection head and the substrate; and selectivelyejecting the liquid electrode material to form the pixel electrode. 16.The method of manufacturing an organic EL according to claim 15 in whichan opposite electrode is formed so as to cover the EL light emittinglayer, said method further comprising the steps of: introducing theliquid electrode material into said function liquid droplet ejectionhead; carrying out a relative scanning between said function liquiddroplet ejection head and the substrate; and selectively ejecting theliquid electrode material to form the opposite electrode.
 17. A methodof forming a spacer in which a particulate spacer is formed between twosubstrates so as to form a cell gap by using the ejection apparatus asset forth in claim 3, said method comprising the steps of: introducing aparticulate material into said function liquid droplet ejection head;carrying out a relative scanning between said function liquid dropletejection head and at least one of the two substrates; and selectivelyejecting the particulate material to form the opposite electrode.
 18. Amethod of forming a metallic wiring in which a metallic wiring is formedon a substrate by using the ejection apparatus as set forth in claim 3,said method comprising the steps of: introducing a metallic wiringmaterial into said function liquid droplet ejection head; carrying out arelative scanning between said function liquid droplet ejection head andthe substrate; and selectively ejecting the wiring material to form themetallic wiring.
 19. A method of forming a lens in which a microlens isformed on a substrate by using the ejection apparatus as set forth inclaim 3, said method comprising the steps of: introducing a lensmaterial into said function liquid droplet ejection head; carrying out arelative scanning between said function liquid droplet ejection head andthe substrate; and selectively ejecting the lens material to form themicrolens.
 20. A method of forming a resist in which a resist of anarbitrary shape is formed on a substrate by using the ejection apparatusas set forth in claim 3, said method comprising the steps of:introducing a resist material into said function liquid droplet ejectionhead; carrying out a relative scanning between said function liquiddroplet ejection head and the substrate; and selectively ejecting theresist material to form the resist.
 21. A method of forming a lightdiffusion member in which a light diffusion member is formed on asubstrate by using the ejection apparatus as set forth in claim 3, saidmethod comprising the steps of: introducing a light diffusion materialinto said function liquid droplet ejection head; carrying out a relativescanning between said function liquid droplet ejection head and thesubstrate; and selectively ejecting the light diffusion material to formthe light diffusion member.